The photodissociation dynamics of isocyanic acid (HNCO) has been studied by the time- sliced velocity map ion imaging technique at 193 nm. The NH(a1△) products were measured via (2+1) resonance enhanced multiphoton ionization. Images have been accumulated for the NH(a1△) rotational states in the ground and vibrational excited state (v=0 and 1). The center-of-mass translational energy distribution derived from the NH(a1△) images implies that the CO vibrational distributions are inverted for most of the measured 1NH(v|j) internal states. The anisotropic product angular distribution observed indicates a rapid dissociation process for the N-C bond cleavage. A bimodal rotational state distribution of CO(v) has been observed, this result implies that isocyanic acid dissociates in the S1 state in two different pathways.