The study was conducted in the urban municipality of Cuernavaca, Morelos, Mexico. From two private veterinary clinics a sample of 1742 dogs during a three year period (1993-1995) were examined to detect the presence of Rhipicephalus sanguineus ticks in any parasitic stage, collecting and identifying the ticks found. The prevalence rates were calculated by month and year and their distribution by age and gender. Chi square tests were used to compare proportions of positive and negative dogs to tick infestation. The prevalence of dog infestation with R. sanguineus was 20% in the period studied and there was no significant difference (P 0.05) between years. Tick specimens were collected throughout the years of the study. The climatic conditions in the study area and the continuous presence of the host favoured the parasite life cycle and 2.5 generations were estimated for each year. There were no significant differences (P 0.05) in the presence of R. sanguineus infestation in dogs by dog age, gender or by year. The main factors influencing the dog tick infestation in this study were probably due to the domestic life habits and the environment of the dogs studied