Intrauterine devices (IUDs) are the second most commonly used contraceptive method in the world. A number of mechanisms have been proposed by which IUDs could interfere with reproductive processes. In this study, the relationship between intrauterine devices and the risk of antisperm antibody (ASA) production in the absence of prior sensitization was investigated. Sixty-two IUD users (group 1) and 42 women with no contraceptive use as a control group (group 2) were included in the study. Six months after the IUD insertion, 4 women in group 1 and 2 women in group 2 with lower genital tract infections were excluded from the study. The sera of the remaining 58 women in group 1 and 40 women in group 2 were evaluated again for the presence of ASA. Twelve patients (20.7%) in group 1 and 12 patients (30.0%) in group 2 had ASA positivity. When we compared the ASA levels in the IUD group with those in the control group, there was no statistically significant difference (p > 0.05). In summary, our data proved that copper-containing intrauterine devices in the absence of prior sensitization do not significantly affect immunity to sperm in sera of women.