4,6-dinitro-o-cresol (DNOC) and 2,2-dichlorovinyl dimethyl phosphate (DDVP), toxic agents used as pesticides in agriculture were injected intraperitoneally to rats (Rattus norvegicus). Physiological saline was given to the control groups. We investigated the effects on pyruvate kinase (PK) enzyme activities in the liver, kidney, brain and small intestine of rats killed by cervical dislocation 0, 2, 4, 8, 16, 32, 64 and 72 hours after the injection. Statistical analysis was performed using the SPSS statistics program. Generally, DDVP increased PK activity in both male and female rats. DNOC caused inhibitions in PK activity in the liver, kidney and the small intestine, as well as in the brain tissues when compared with control groups.