This paper describes a simulation model to evaluate different control strategies for Boophilus microplus. The model combines a dynamic life-history module for tick-population dynamics with other modules for vaccination, sterile-hybrid larval release and use of acaricide dipping vats. The tick life-history module considers the cattle's nutritional level and allows for distribution of ticks by age at all stages of growth. Appropriately, the model was sensitive to host resistance and to host-nutritional status. The validity of the life-history module - as well as that of the vaccination and acaricide dipping-vats modules - was demonstrated by comparing simulated and real data for several geographical locations in Cuba and Brazil. Optimum tick-control strategies for the first year of vaccination were designed and the effect of long-term vaccination on tick population was also studied. (C) 1999 Elsevier Science B.V. All rights reserved.