The effect of serial biopsy sampling on S‐ and G₂+M‐fractions in lower abdominal skin from leg ulcer patients was studied by single‐nuclei DNA flow cytometry. Significant differences in both measurements were found in four biopsies taken at equal intervals within 24 h, but not in four biopsies taken at noon on four consecutive days. The variation in S‐fractions was closely related to the injury from previous biopsy sampling(s) while the G₂+M‐fraction variation tended to follow the time of the day. The study indicated local as well as systemic effects from previous biopsy sampling.