The data from 847 births from a home birth practice where six different positions were used for delivery permitted the analysis of the effect of maternal position on perineal outcome. The obstetrical log also permitted the identification of other factors that influenced maternal position and perineal outcome. The most frequently used birth position was semisitting, in 83% of the births. The incidence of episiotomy was 7%, and of lacerations, 55%. Factors significantly associated with maternal position were fetal presentation (breech) and birth attendant. Fetal position or presentation, infant weight, parity, and the birth attendant were significantly associated with perineal outcome. The predominant use of the semisitting position may explain why there was no association between maternal position and perineal outcome. The influence of the birth attendant on both these factors suggests the impact of attitudes, skill, or ease in assisting the birth on these aspects of obstetrical practice.