Infection is a well-recognized triggering factor for both guttate and chronic plaque psoriasis. We investigated prospectively 13 patients with recalcitrant psoriasis exacerbated by recurrent tonsillitis, who underwent tonsillectomy between 1990 and 1993. There were 12 female patients and one male, with a mean age of 17 yr (range 6-28). Six patients had guttate psoriasis resistant to standard treatments and seven patients had chronic plaque psoriasis exacerbated by tonsillitis that was severe enough to warrant at least one admission to hospital. Patients were followed by chart review and postal questionnaire. Psoriasis was cleared completely after tonsillectomy in five out of the six patients (83%) with guttate psoriasis and was improved in one patient. Two out of seven patients with plaque psoriasis (29%) were cleared, two (29%) were improved and three (42%) were unchanged. We conclude that tonsillectomy may be a successful treatment modality in selected patients with recalcitrant guttate or chronic plaque psoriasis.