One hundred and eighty adult Clarias albopunctatus (mean weight 160±2.7g) were subjected to sublethal concentrations of Gammalin 20 and Actellic 25 EC (0, 0.3;and 1.0 µg/l) in a static bioassay renewal system for 18 days. The changes in the activities of the liver and serum lac ate dehydrogenase (LDH) during the period of exposure were studied. The exposure of C. albopunctatus to these pesticides evoked significant increase (P< 0.05) in both the liver and serum LDH activities. There was a progressive increase in both the liver and serum LDH activities following exposure to the pesticides. When compared with the control, the LDH activities were significantly higher (p < 0.05) in the treatment groups. The LDH activities in both the liver and the serum were higher in the fish exposed to Gammalin 20 than in the fish treated with similar concentrations of Actellic 25 EC. The serum LDH activity in the group exposed to a mixture of 0 3µg/l of Gammalin 20 and Actellic 25 EC was significantly higher the activities in the fish exposed the either 0.3 µg/l Gammalin 20 or Actellic 25 EC. These observations suggest that these pesticides affect the energy metabolism of the fish.