In the Sudan, ticks and Tick-borne Diseases (TBDs) with subsequent costs of control and treatment are causing substantial economic loss. Control of ticks is mainly by chemical insecticides. The rising environmental hazards and problem of resistance has motivated research on biological agents as alternative methods of control. The present study aims at controlling livestock ticks using fungi for their unique mode of action besides their ability to adhere to the cuticle, to germinate and penetrate enzymatically. The study was conducted to evaluate the fungus Metarhizium anisopliae for tick control as an alternative mean to chemical acaricides. Pathogenicity of the fungus was tested on different developmental stages of the tick Hyalomma anatolicum. The fungus induced high mortality to flat immature stages. It, also, affected reproductive potential of the females. Egg laid, hatching percent, fertility and moulting percent of immature stages were significantly (p < or = 0.05) reduced. It was, also, shown that the fungus had ability to adhere to the cuticle and penetrate the integument of the tick. Conidia of the fungus were isolated from their internal tissues. This phenomenon is important in considering fungi as bioinsecticides. Infection of eggs laid by treated engorged female ticks, with the fungus might demonstrate suggesting transovarian transmission. The use of M. anisopliae to control ticks is discussed.