The results of in vivo evaluation of deltamethrin 7.5 % pour on revealed that single application caused 100% elimination of Boophilus annulatus hard ticks from naturally infested cows under treatment within 2-3 weeks. There was neither any reinfestation nor undesirable side effect up to 45 days post treatment. Deltamethrin 7.5% pour on seems to be very effective against tick infested cows, safe for use and easy for application. In vitro evaluation, B. annulatus tick species exposed to hair (10 minutes) collected from cows previously treated with deltamethrin 7.5% pour on show some degree of paralysis and mortality varies according to time of collected hair post treatment. The most effective result was observed on hair collected 14 days post treatment, while hair collected 35 days post treatment was the least, since the speed of killing activity slows down gradually with time pass. The predilection site of lice, Haematopinus tuberculatus among buffaloes were the wither region (47.6%) followed by the neck and dewlap (45%), while the cheek was (0.16%) the lowest predilection site for buffaloe lice. In vivo evaluation, of deltamethrin 7.5% pour on against buffaloe's lice was 100% on day 7 post treatment compared to control group. Animal showed relief from symptoms of itching which continued for 35 days post treatment. In vitro evaluation, the mortality of lice was started 15 minutes after exposure and completed after 30 minutes from exposure to insecticide.