Dissipation of pentachlorophenol (PCP) in red paddy soils under aerobic and anaerobic conditions were investigated under four long-term fertilization treatments as follows: (1) no fertilizer (the control, CK), (2) application of urea (N), (3) application of organic fertilizer (OM), and (4) N+OM. The results showed that the dissipation of PCP followed one-order kinetic equation under aerobic or anoxic conditions, and the half-lives of dissipation under aerobic condition in soils were 26.9, 27.7, 21.5 and 20.6 days for CK, N, OM and N+OM respectively. The half-lives of dissipation under anaerobic condition were 30.8, 32.2, 27.1 and 25.9 days respectively. The results suggested that long-term application of organic fertilizer significantly accelerated the dissipation of PCP in soils under aerobic or anoxic conditions due to the significantly higher organic matter content and microbial activity, and dissipation rate under aerobic condition was higher than that under anaerobic condition.