AIMS--To assess the role of human papillomavirus in the pathogenesis of adenocarcinoma in situ, endocervical glandular dysplasia (a presumed precursor of adenocarcinoma) and endocervical glandular epithelial giant cell change. METHODS--Viral detection was carried out using an in situ hybridisation technique on paraffin wax sections. Biotinylated probes for human papillomavirus types 6/11, 16/18, 31/33/35 were used with a colorimetric detection system. RESULTS--Nine out of 21 (43%) cases of adenocarcinoma in situ contained human papillomavirus types 16/18, one of which was also positive for 31/33/35. Ten cases of glandular dysplasia and four cases of glandular epithelial multinucleation did not react with the probes used. CONCLUSIONS--These results indicate that while adenocarcinoma in situ is strongly associated with human papillomavirus infection, endocervical glandular dysplasia and glandular epithelial multinucleation are probably not associated with the virus.