Effects of repeated administration of diminazene aceturate (Hoechst Veterin r GmbH. Ger- many) that has been introduced as effective compound against Babesiosis and trppanosomiasis were investigated in dogs experimentally infacted with Babesia gibsoni. Adull mongrel dogs of both sexes were inoculated will nonpreserved infected blood and then maintained chronic anemia. A single dose of diminazene aceturate of 7mg/kg b.w. was administrated intramnuscularIy on day 7.1 arid ,7. Clin- ical and hcmatological findings following inoculation and medication were observed and 7enlm bio chemical analysis also was monitored. Parasitemia was detected between 3 and 6 days after inoculation. The rate of parasitized erythrocytes,1 in peripheral blood reached the peak on the 13th day and was maintained the percentage of 0.1 to 1.0 until the medication of diminazene aceturate. RBC was significantly (p<0.01) decreased on the 3rd day and then kept on decreasing. The lowest value was observed on the 16th day. WBC remained generally within normal ranges. PCV revea1ed the sig-nificant (p<0.01) decrease within the range of 24-27% and platelet was significantly (p<0.05) decreased during the period. Senum chemical values (ALT, AST. total bilirubin. LDH BUN, area- tinine, total protein. albumin and glucose) were within normal ranges during the experimental period. Serum CPK values were significantly (p<0.01) increased on the 3rd day. There was no clinically, sig-nificant difference in a single dose of diminazene aceturate of 7 mg/kg b.w. But the administration of diminazene aceturate of 14 mg/kg b.w. revealed vomiting and anorexia and one dog died in 30 hours after administration. The administration of 14mg/kg b.w. resulted in vomiting, salivation, actor- exia, tremor of head and involuntary movement and one dog died in 27 hours after administration. WBC, RBC, PCV and Platelet values were no significant difference and hematological findings revealed persistent anemia and thrombocytopenia during chronic anemia after inoculation. AST activity its was significantly (p<0.01) increased 11\`from 3 days after medication and AST activity was on the same trend. Serum CPK activity revealed significant (p<0.01) increase within 6 hors)\`s after every administration and decreased in 48 howl·s after administration.