A survey of the prevalence of pterygium was performed, and a random proportional sampling was taken of 367 patients in four hospitals in Lima, Peru. An overall incidence of 31.06% was found, with a statistically significant increase in prevalence with regard to age. No statistically significant differences with regard to sex or occupation were found. Although incidence of pterygium was higher in men and in outdoor workers, these factors were not statistically significant.