Over an 8-year period five patients with suprasphincteric fistula and two with extraspincteric fistula a primary transsphincteric track were treated with fistulotomy, using delayed seton technique. In all but one case the fistulas had caused considerable morbidity, involving multiple episodes of abscess drainage and attempts to lay open the track before the correct diagnosis was established. No patient had recurrence of fistula and, despite complete division of the anorectal ring, and sphincter pressures were well maintained and anal continence was unchanged. The results suggest that the delayed seton technique is useful in the treatment of these very rare and complicated fistulas.