This chapter examines the history of the most frequent metres in early Latin comedy, iambic senarii and trochaic septenarii. While persisting into the classical period, these metres become less prominent; early funerary epigrams can still be composed in iambic senarii, but elegiacs predominate, and there are also significant changes in prosody and versification rules. No sharp chronological contrast is observed in the tradition of dramatic iambo-trochaics. The main differences between early and classical iambo-trochaics are not metrical, but prosodic; they consist above all in the elimination or reduction of prosodic variants, such as original length of vowel endings (-āt for -ăt), iambic shortening, sigmatic ecthlipsis; these phenomena are common in Plautus but absent, e.g., from Varro and Phaedrus. Conversely, lengthening with muta cum liquida, which is absent from comedy, is well attested in imperial iambo-trochaics, including e.g. Phaedrus and inscriptions. Even in this respect, however, one should be wary of neat chronological generalisations, especially because the reduction of prosodic variants is already attested in early authors such as Terence.