Objective: Todetermine thepresence ofChlamydia trachomatis inhydrocele fluid. Methods: 90malepatients withhydrocele oftunica vaginalis fromanendemic areaforban- croftian filariasis wereinvestigated forthepresence ofChlamydia trachomatis intheir hydrocele flu- ids. C trachomatis antigen detection tests-a direct immunofluorescence

assay andanenzyme immunoassay along withpolymerase chain reaction assay foramplification ofa517bpfragment ofCtrachomatis endogenous plasmid-were usedinthis study. Thepatients werealso tested for thepresence ofmicrofilaria intheir hydrocele fluids andnight blood. Histopathological examination wascarried outtodetect adult filarial wormintunica vaginalis testes. Results: Eight (8.88%) patients hadchlamydia antigen inthehydrocele fluids; C trachomatis plasmid sequences could beamplified fromfive ofthese. Seven(7.77%) patients hadmicrofilaria inthehydrocele fluids, three ofthemhaving adult wormintunica vaginalis. Conclusion: C trachomatis infection mightbeassociated withhydrocele insomeofthese patients. (Genitourin Med1997;73:503-505)