Incidence of tick infestation in Puerto Rico was evaluated, as well as control mechanisms, and economic losses due to ticks in dairy herds. Data were obtained by means of questionnaire information from 261 dairy herds representing 85% of all dairies in Puerto Rico. Seventy-one percent of those interviewed confirmed tick infestation in their herds. To control tick infestation 97% used fumigation of animals; 8%, fumigation of structures. The most common method used for pesticide application (73%) was by fumigating animals in chutes by using a pump. Tick incidence was 72% in dry cows and 54% in milk cows. Poisson regression analysis showed no significant differences in mortality rates between the northeast and northwest zones of the island. Differences were found among municipalities. The average annual cost of the tick control program that farmers maintained was $28.09 per cow but mortality losses are much more costly.