Although continuous support during childbirth is recommended by the World Health Organization (WHO) and has well-established benefits, the practice is still not routinely implemented in all maternity settings. We studied the possible effect of an additional lay companion (other than the partner) on childbirth experience and postpartum post-traumatic stress disorder (PTSD). Two hundred and forty-six women, who gave birth in maternity wards of a large tertiary health center in Israel, responded to questionnaires in person at 1–4 days (Demographic questions and the childbirth experience questionnaire) and on-line at 8–10 weeks postpartum (City Birth Trauma Scale). Obstetric data were taken from the medical files. Women who were accompanied by their partners and an additional companion were lower in birth-related PTSD symptoms (M = 1.17, SD = 2.61) than women accompanied by only their partner (M = 1.53, SD = 2.79) (F(2, 240) = 4.0, p < 0.05). Women who had a single companion (M = 1.44, SD = 2.61) showed more birth-related PTSD symptoms than women who had two or more companions (M = 1.17, SD = 2.52) (F(1, 241) = 6.4, p < 0.05). In addition, women who had a single companion were higher in general PTSD symptoms (M = 3.91, SD = 4.73) than women who had two or more companions (M = 2.31, SD = 4.29) (F(1, 241) = 4.2, p < 0.05). No differences were found in childbirth experiences of women with single or multiple companions. Allowing more than one lay companion (other than the partner) may be a simple cost-effective way of providing beneficial support in all birth settings, promoting respectful maternity care and reducing childbirth-related PTSD levels and by that future psychopathology sequela.