Display omitted •The product state distributions in trimethylamine photodissociation were measured.•The CH3 photofragments showed dual ring-like scattering distributions.•The slow CH3 fragment was ascribed to the production of the excited state N(CH3)2.•The energy threshold of CN fission was located between the S2 and S1 state origins. The photodissociation dynamics of trimethylamine, N(CH3)3, was studied using ion-imaging. The photolysis wavelength was scanned over the 200–236 nm region, where the S1(3s) and S2(3p) states were excited with varying relative populations. The dissociation threshold of CN bond fission was found at 42,500 cm−1, which is located between the S1(3s) and S2(3p) origins. The final-state distributions were qualitatively insensitive to the photoinitiated states, indicating a dissociation mechanism following ultrafast electronic dynamics. The CH3 photofragments showed dual ring-like scattering distributions, which were ascribed to branching to the CH3 + N(CH3)2 (A∼2A1) and CH3 + N(CH3)2 (X∼2B1) pathways.