Pathways, energetics, and mechanisms of the 193 nm photodissociation of acetyl cyanide (CH3COCN) have been investigated using high-resolution transient frequency modulation (FM) spectroscopy and photofragment translational spectroscopy. Vibrational and rotational state distributions of CN fragments measured by FM spectroscopy are in goad agreement with previous work, The quantum yield of CN is found to be 0.9 +/- 0.2. State-dependent translational energy distributions are nonstatistical. The laboratory-frame anisotropy of both velocity and angular momentum of CN fragments is vanishingly small, yet significant v.j correlations are observed, indicating a preference for the CN angular momentum to be perpendicular to the recoil velocity, Photofragment translational spectroscopy provided independent confirmation of kinetic energy distributions and fragmentation pathways. The combined measurements are consistent with the strong preference for primary CN elimination over CH3 elimination despite a large difference in C-C bond strengths. The primary acetyl radicals undergo virtually complete secondary dissociation.