Eugenol was investigated for the treatment of Haemoproteus columbae (H. columbae) infected squabs (young domestic pigeons, Columba domestica). Thirty naturally-infected squabs were divided into three groups of 10 each. One group was treated with Eugenol, while the positive and negative control groups were administered buparvaquone (Butalex®) and distilled water, respectively. The number of infected red blood cells (RBCs) was calculated in all groups before and after treatment at 4-day intervals for 16 days. The results showed a significant therapeutic effect of Eugenol, with a progressive decrease in the number of infected RBCs from 89.20 +− 2.11 before treatment to 0.90 +− 0.31 at the end of treatment (P≤0.05). Butalex® was able to suppress the number of infected RBCs from 93.70 +− 1.72 before treatment to 0.90 +− 0.35 at the end of the experiment (P≤0.05). Eugenol showed therapeutic effects against H. columbae and may be regarded as a candidate for further studies to develop new drugs against blood parasites, in both animals and humans.