Abstract Background The first minutes after birth are critical to reducing neonatal mortality. Helping Babies Breathe (HBB) is a simulation-based neonatal resuscitation program for low resource settings. We studied the impact of initial HBB training followed by refresher training on the knowledge and skills of the birth attendants in facilities. Methods We conducted HBB trainings in 71 facilities in the NICHD Global Network research sites (Nagpur and Belgaum, India and Eldoret, Kenya), with a 6:1 ratio of facility trainees to Master Trainers (MT). Because of staff turnover, some birth attendants (BA) were trained as they joined the delivery room staff, after the initial training was completed (catch-up initial training). We compared pass rates for skills and knowledge pre- and post- initial HBB training and following refresher training among active BAs. An Objective Structured Clinical Examination (OSCE) B tested resuscitation skill retention by comparing post-initial training performance with pre-refresher training performance. We identified factors associated with loss of skills in pre-refresher training performance using multivariable logistic regression analysis. Daily bag and mask ventilation practice, equipment checks and supportive supervision were stressed as part of training. Results One hundred five MT (1.6 MT per facility) conducted initial and refresher HBB trainings for 835 BAs; 76% had no prior resuscitation training. Initial training improved knowledge and skills: the pass percentage for knowledge tests improved from 74 to 99% ( p