Sample preparation is an important step in the detection of viral DNA by the polymerase chain reaction (PCR) technique. The method used should achieve release of cellular DNA with the minimum of manipulation steps so as to reduce the possibility of contamination. The present report demonstrates that either microwaving or 20 min of boiling in the heating block of a thermal cycler lead to satisfactory results in the detection by PCR of human papillomavirus in cervicovaginal epithelial cell specimens obtained by lavage. Since each of these methods uses only one step the possibility of contamination is greatly reduced compared to the widely used proteins K/nonionic detergent extraction procedure.