Recurrent acute leg cellulitis (ALC) known to occur in patients with impaired venous or lymphatic circulation was studied in 126 patients after radical vulvectomy with lymphadenectomy through the years 1973 to 1985. Among these patients surveyed for a total period of 6153 patient months, 33 (26%) experienced 75 episodes of ALC. Recurrent attacks were frequently observed. Although antimicrobial treatment was often started, clinical signs resolved also in 9 patients without antimicrobial treatment. To prevent recurrencies penicillin prophylaxis was given to 23 patients. Only 1 of them had once a mild attack of ALC, whereas recurrent attacks occurred frequently in those patients not receiving penicillin prophylaxis. Although penicillin prophylaxis was successful in preventing the recurrence of ALC the risk-benefit ratio of this approach has not been ascertained. The etiology and pathogenesis of recurrent ALC is discussed. Analysis of a number of assumed risk factors for ALC showed that the frequency of ALC was significantly higher in patients colonized with beta-hemolytic streptococci, mainly group B, than in patients not colonized with these microorganisms just prior to surgery. This suggests that non-group A beta-hemolytic streptococci are involved in the onset of ALC in patients after radical vulvectomy. However, portals of entry for microorganisms were not apparent in any of our patients.