This study was aimed to investigate the potential protective effects of propolis in some blood parameters of juvenile tilapia exposed to a dinitroaniline herbicide pendimethalin. The fish exposed to 1/10 of the 96-h LC50 pendimethalin (0.042 mg/L), 2 mg/L propolis and 0.042 mg/L pendimethalin+2 mg/L propolis for 24 and 96 h. Results showed that pendimethalin and pendimethalin+propolis groups a significant decrease in the red blood corpuscles (RBCs), hemoglobin (Hb) and hematocrit (Hct) level as well as a significant increase in mean corpuscle volume (MCV) level were observed for both period. Propolis alone exposure caused a sudden and sharp rise in RBC, Hb and Hct level were observed during 24 h as well as a considerable decrease of these parameters during 96 h. Alanine aminotransferase activity increased at all exposure groups at 24 and 96 hours while aspartate aminotransferase activity significantly decreased. Also, pendimethalin, propolis and their mixture caused a decrease in serum ions levels. In conclusion, these results suggested that pendimethalin and propolis induced anemic condition and disrupted metabolic processes and osmoregulation in fish. In addition, even though the toxic effects of pendimethalin on blood parameters have been slightly prevented by the effect of propolis but it was inadequate.