The World Health Organization identified the promotion of "Nurturing Care Environments" as a global health priority. Responsive caregiving, 1 of 5 domains describing nurturing care, is critical for healthy child development. Relatively little research has evaluated population-level interventions aimed to increase responsive caregiving during the first 1,000 days of an infant's life. In this pilot study, we evaluated an intervention designed for population-level dissemination that targeted responsive caregiving. The self-guided behavioral skills training aimed to teach mothers to imitate infant vocalizations. The intervention was delivered within an on-line asynchronous training. All 3 mothers increased vocal imitative behavior following training without receiving coaching or behavior-specific feedback from an implementer. The results offer a preliminary proof of concept with implications for population-level intervention design and evaluation.