- The meaning of the line "Rangers at the core" in the Power Rangers Zeo theme song: even though the Rangers had different powers and equipment, they were, at the core, still the same Rangers continuing their fight against evil in the tradition they'd followed in the Mighty Morphin' series.
- "Mondo's Last Stand" featured Rocky displaying an inferiority complex. Whilst it never got brought up again in Zeo, this would eventually lead to Rocky's Game-Breaking Injury in Turbo: A Power Rangers Movie.
- Prince Gasket attempts to brainwash Tommy into becoming the ruler of the Machine Empire in "King for a Day". In the episode immediately following it, "A Brief Mystery of Time", side effects from the brainwashing allows Tommy to recognize that the exact same day is looping repeatedly. It may be possible that Tommy's sudden boost in intelligence and memory skills (as seen in Dino Thunder) are also due to these side effects.
- Rita being pregnant with their child by the events of the season finale as per Word of God explains quite nicely why she and Zedd left at the end of the season, rather than resume conquering — they were taking time off to raise their son. In addition they may have gone off to another planet that wasn't as well defended to build their forces up so they'd have a better footing when they came back.
- If one really thinks about it, the Zeo Rangers as described in the series canon are, literally, the most powerful rangers of all time. The Zeo Crystal was an infinitely self-strengthening power source that would never stop growing more potent. The Zeo Ranger arsenal of weapons and zords was growing more complex and varied with every major episode. But this leads to a serious question that was never answered in any way. Why did they stop using the Zeo powers and move to the Turbo powers? Tommy at the least clearly retains the Red Zeonizer all the way up to Forever Red and it's unlikely he got rid of it afterward, unless that was the base he used to develop the Dino Gems. But that also begs the question of "Why mess with the Zeo Crystal and turn it into something clearly less powerful?" The only answer that logically comes to mind is that the Zeo Crystal is not as much of a penalty free power source as first believed. As we see with season team-ups and was Lampshaded in Power Rangers RPM, morphing tends to cause explosions. Imagine what Zeo morphing would eventually do. That's right, the Zeo powers were pocket supernovas waiting to happen; since they were self-strengthening and ever-growing, it's quite possible that they could eventually reach a stage where the Rangers' bodies are no longer able to tolerate them, much like with Jason and the Gold Ranger powers. One interesting theory was the escalating power of the Zeo crystal would risk the Rangers losing touch with their humanity; the extreme power level was required when facing the threat of Mondo and the Machine Empire, but with Divatox, they could relatively safely 'downgrade' to a power level that meant they had to struggle a bit more but wouldn't risk being morally compromised.
- The Tengas being able to squeak out a victory on the Cogs makes sense when you remember one thing: Rita and Zedd have spent the time since they ran off with Master Vile, who upgraded the Tengas back in season 3. Or rather, a Pyrrhic victory, due to the fact the Machine Empire can replace Cogs quickly, and had more on the Moon, while Rita and Zedd were down to one Tenga and can only get more if they can find their eggs. So, it makes sense that after that one survivor runs away, they are not seen again in the rest of the episode and Zedd opts another way to defeat King Mondo.
- Rita and Zedd not fearing the Machine Empire anymore makes a lot more sense when you remember Rita got an upgraded staff that let her create a monster more powerful than most of the Empire's. They don't fear Mondo anymore because Rita's now as strong if not stronger than he is.
- Early on, Mondo threatens to send Klank to mine on the "dark side of Alpha Centauri", which sounds like writers not knowing astronomy, but think about it, he's a conqueror, what did he do to the Alpha Centauri star system in the Power Rangers universe that there would be a "dark side". Perhaps it was Zedd that did something since it was mentioned that Zedd ruled over "darker regions of the galaxy", the darkened portion of Alpha Centauri having been conquered by the Machine Empire within the last year or two while Zedd was tied up on Earth.
- It might initially seem off that the Gold Ranger has trouble with the Varox when the other Rangers can do more damage to the monster in question, but this can be justified on the assumption that Varox was created/trained/whichever term applies to specifically battle the Gold Ranger; as a result, pitted against a whole team of Rangers he wasn't expecting to fight, he finds himself a victim of Crippling Overspecialization.
- Ever wonder why Zeozords 1 and 2 have to be pulled into battle by Zeozords 3 and 4 by big chains? Well, they had to make sure that not only did Zeozords 1 and 2 have enough room for their missiles and cannons (since they were supposed to be the "arsenal" of the Zeozords), but also be structurally stable enough to hold up the Zeo Megazord during battle (and, further down the line, the Zeo Megabattlezord, which was really top-heavy), and handle movement for the Megazord too (the ZMBZ was top-heavy enough that it never moved its' legs post-combination). Between the arsenal, stability issues and the need for movement, Billy simply didn't have enough space to fit any self-propulsion systems in Zeozords 1 and 2, and improvised the chain idea as a short-term solution (which he never got around to fixing before leaving).
Fridge / Power Rangers Zeo