INTRODUCTION Genital chlamydial infection is the most commonly reported bacterial sexually transmitted disease worldwide. It poses a public health problem of epidemic proportions. Most primary infections are asymptomatic. The prevalence is highest in young, sexually active women. Untreated or poorly treated cases result in endosalpingeal damage and destruction of tubular architecture with multiple sequelae, including tubal factor infertility and ectopic pregnancy. This study sought to determine serological evidence of prior chlamydial infection in patients with tubal factor infertility and to ascertain any risk association between Chlamydia infection and tubal factorinfertility in Port Harcourt, South- South Nigeria. OBJECTIVE The main objective of this study was to determine serological evidence of prior chlamydial infection among patients with tubal factor infertility by detecting the presence of immunoglobulin G antibodies in their sera and to ascertain any association between the infection and tubal infertility. METHODOLOGY This was a case-control study in which 188 study subjects were drawn from the University of Port Harcourt Teaching Hospital. This number was divided into two, with 94 consisting of women with confirmed tubal factor infertility using hysterosalpingogram, who served as cases, and the other 94, of women with intrauterine pregnancy drawn from the antenatal clinic as controls. Their socio-demographic characteristics and the pattern of sexual behaviour were documented in the profoma provided. Statistical analysis was done using SPSS version 17 statistical software