Cervical cells were screened for human papillomavirus (HPV) infections by in situ filter hybridization in 108 patients wearing intrauterine contraceptive devices. The cells were tested for the presence of HPV 6, 11, 16, 18 DNA. In 86 cases (79.6%) no reactions were obtained with 32P-labeled HPV DNA probes. 22 smears (20.3%) were positive for HPV: type 6 and 11 sequences were demonstrated in 17 cases (3 of them carried both). 4 smears hybridized with the probe for oncogenic HPV 16 and one with that for oncogenic type 18. All these five patients had normal smears and no abnormality on colposcopy.