A format where the main characters solve a mystery each weekly episode. AlwaysMurder usually applies as well, but medical, other scientific, or supernatural mysteries can be solved instead.

Almost every DetectiveDrama sticks primarily to this format, though some recent shows (eg. the ''Series/{{CSI}}'' franchise) has upped the ante to '''two''' murders per week, one in the A plot and the other in the B plot. Notable exceptions are ''Series/MurderOne'', which devoted an entire season to each case, and the early seasons of ''Series/HomicideLifeOnTheStreet'', in which detectives would typically work three or four cases at the same time, each case taking several episodes to close (In fact, sometimes they wouldn't solve the case at all, and a case opened in the first episode remained open in the finale). In later seasons, they yielded to [[ExecutiveMeddling network pressure]] and became a standard MysteryOfTheWeek show.
----
!!Notable Examples:

* ''Series/AgathaRaisin''
* ''Series/{{The Avengers|1960s}}''
* ''Series/{{Banacek}}''
* ''Manga/CaseClosed''
* ''Series/{{Castle|2009}}''
* ''Series/ColdCase''
* ''Series/ColonelMarchOfScotlandYard''
* ''Series/{{Columbo}}''
* ''Series/CrazyLikeAFox''
* ''Anime/DanganronpaTheAnimation'' has one every two weeks, adapted from the [[VisualNovel/DanganronpaTriggerHappyHavoc original game]]'s one per chapter.
* ''Series/DeathInParadise''
* ''Series/DiagnosisMurder''
* ''Series/DocMartin'': Either a single patient with a strange illness or a town epidemic.
* ''Series/TheDoctorBlakeMysteries''
* ''Series/ElleryQueen''
* ''Series/{{Elementary}}''
* ''Series/{{Engrenages}}'' inverted the case of ''Homicide'' by having Mysteries of the Week in its first two seasons, but then abandoning them entirely in favour of having multiple series-long arcs instead of just one.
* ''Series/{{Forever|2014}}''
* ''Series/{{House}}'' also arguably qualifies.
* ''Series/LawAndOrder'' and its spin-offs.
* ''Literature/LessonsForAPerfectDetectiveStory''
* ''Series/{{Monk}}''
* ''Series/McMillanAndWife''
* ''Series/McCloud''
* ''Series/MidsomerMurders''
* ''Series/MissFishersMurderMysteries''
* ''Series/MrsColumbo'' (later called ''Kate Loves A Mystery'')
* ''Series/MurdochMysteries''
* ''Manga/{{Mushishi}}''
* ''Series/MurderSheWrote''
* ''Series/NestorBurma''
* ''Series/Numb3rs''
* ''Series/PokerFace''
* ''Series/{{Psych}}''
* ''Series/{{Rejseholdet}}''
* ''Manga/RonKamonohashiDerangedDetective''
* ''Franchise/ScoobyDoo''
* ''Series/{{Shoestring}}''
* ''Series/VampireProsecutor''
* ''Series/{{Vera}}''
* ''Series/VeronicaMars''
* ''Series/WhodunnitUK''
----