['A chronically infected sacral wound requiring repeated shaving, cleansing and dressing after treatment of pilonidal sinus disrupts both work and social activity.', 'To compare delay in pilonidal sinus wound healing after laying open with that after primary closure.', 'Healing time and recurrence were recorded in a consecutive series of 102 patients in one hospital undergoing either asymmetric primary closure (Karydakis procedure) by a single surgeon or laying open by other surgeons.', 'The interval from operation to cessation of wound dressing was significantly shorter (log rank test, P\u2003<\u20030.0003) after primary closure (median 3\u2003weeks, iqr 3-6) compared with laying open (median 6\u2003weeks, iqr 4-8). No primary closure (0%) and 10 laid open (19%) wounds remained unhealed at 10\u2003weeks from operation (2\u2003×\u20032 contingency table, P\u2003=\u20030.003). No significant difference was demonstrated (Mann-Whitney U-test) between healing time in elective (median 3\u2003weeks, iqr 3-6) compared with emergency (median 3\u2003weeks, iqr 3-3) admissions treated by primary closure.'] Is prolonged delay in healing after surgical treatment of pilonidal sinus avoidable?