Objectives. To test the hypothesis that there is a bimodal spring-fall seasonal predilection for acute testicular torsion and to compare our series with those previously reported outside the United States that support a seasonal predilection. Methods. A retrospective chart review of operative notes was performed for all cases of acute torsion of the testis confirmed at surgery during a 15-year period at our institution. The diagnosis, child's age, and date of occurrence were verified; 135 confirmed cases were identified. Results. The months with the highest incidences of acute testicular torsion were December (14%) and January (11%). Thirty percent of cases occurred in the fall (October, November, December), 24% in the winter (January, February, March), 22% in the summer (July, August, September), and 23% in the spring (April, May, June). Conclusions. No statistically significant differences were seen with regard to seasonal or monthly occurrence of acute torsion. However, the "cold" weather trend identified is consistent with those of larger international studies. It is possible that our regional monthly temperatures do not vary enough to demonstrate whether cold weather influences the incidence of torsion. To our knowledge, this is the only reported series regarding a seasonal predilection for torsion in the United States. A multi-institutional, prospective study representing all regions within the United States is needed to establish the significance of season and climate on testicular torsion. © 2003, Elsevier Science Inc.