A retrospective study of 89 patients undergoing 98 arthroscopies of the knee in which a medial synovial plica was noted was undertaken. In 86 cases, the plica was deemed to be pathological and was resected arthroscopically. The symptoms and signs of these patients were noted preoperatively and the results of their operation noted in the outpatient department and subsequently by questionnaire. Our findings agree with other authors in this field and we propose that arthroscopic resection of a pathological plica is a worthwhile procedure.