Dissociative excitation of CH3COCN to produce CN(B-X) and CN(A-X) fluorescence was studied by resonance enhanced multiphoton excitation at 292 nm. The laser power dependence of the CN(B-X) fluorescence intensity and the lifetime of the one-photon excited S-1 state showed that CN(B) formation takes place in the direct two-photon and two-body dissociation mechanism, CH3COCN+2hnu -->CH3CO(X)+CN(B). Vibrational and rotational energy distributions of the nascent CN(B) fragment were determined by a simulation analysis of the dispersed fluorescence spectrum. The vibrational distribution was found to be of the relaxed type and rotational distribution in each vibrational state could be approximated by a Boltzmann distribution. The best-fit vibrational distribution of CN(B) was N-v(')=0: N-v(')=1:N-v(')=2=1.00: 0.25: 0.07 with the respective rotational temperatures of T-r(v(')=0)=2600 K, T-r(v(')=1)=1000 K, and T-r(v(')=2)=900 K. The internal state distributions were found to be hotter than those predicted by the statistical model with complete energy randomization within the excited molecule. The results indicate a dissociation mechanism where both the vibrational energy deposition in the photoexcitation and available energy redistribution before the bond breakage are limited within the modes of the skeletal CCOCN structure. Possible decay channels other than the CN(B) production, upon two-photon excitation at 292 nm, are also discussed based on the potential surfaces previously predicted. The formation of CN(A) presently observed in the direct two-photon excitation can be interpreted as the dissociation of the electronic excited intermediate states, populated competitively via internal conversion(s) from the upper electronic states. To obtain a deeper understanding of higher excited states of acetyl cyanide, the vacuum UV absorption cross section was also determined in the 110-200 nm region, using a synchrotron radiation source. (C) 2003 American Institute of Physics.