The mechanism for the HCNO + F reaction has been investigated at the B3L YP/6-311 ++G(3df,2p) level of theory. The potential energy surface (PES) for this system shows that there are ten different product pathways: PRI (CNO* +HF), PR2 (HCN + OFO), PR3 (HCF: + NO), PR4 (OCNF + H), PRS (FCN + *OH), PR6 (HF + *CNO_cy), PR7 (FCNO + H), PR8 (OCNH + F). PR9 (OCN* + HF) and PRIO (CO + NHFO). The results indicate that PRI (CNO* +HF), PR3 (HCF: + NO) and PR5 (FCN + OH) are the major product channels with minor contributions from PR4 (OCNF + H), PR6 (HF + *CNO_cy), PR8 (OCNH + F), PR9 (OCN* + HF), PRIO (CO + NHFO) whereas the other channels for PR2 (HCN + OFO), PR7 (FCNO + H) are less favorable.