Background. During the past years a major change in the use of delivery position has occurred in Sweden. Recumbent delivery positions have been replaced by a variety of positions: squatting, standing, lateral, kneeling and quadruped. The consequences of this shift in obstetrical practice for development of perineal lacerations are largely unknown.Method. Retrospective comparison of uncomplicated deliveries in standing (n = 650) and sitting (n = 264) position with respect to third degree lacerations.Results. The standing and sitting delivery group were similar with respect to maternal, infant and delivery characteristics. The frequency of third degree tears was 2.50% in standing and 0.38% in sitting birth position (p<0.05). In nulliparous women, third degree tears occurred in 4.2% in standing and 1.0% in sitting position.Conclusion. The present data implies that the risk of third degree lacerations is considerably higher (7x) in standing than in sitting birth positions.