Home-visitation programs have improved child development in low- and middle-income countries, but they are costly to scale due to their reliance on trained workers. We evaluated an inexpensive and low-tech alternative with 2,433 caregivers of children aged 6 to 30 months served by 250 public childcare centers in Uttarakhand, India: automated phone calls offering parenting advice. The intervention was implemented largely as intended, with more than two-thirds of caregivers completing at least 10 calls. Yet, counter to expectations, it had negative but statistically insignificant effects on caregivers’ knowledge and interactions with their children, reduced their self-efficacy (by 0.11 standard deviations), and increased their anxiety (by 0.10 standard deviations). Consistent with this pattern, it had precisely estimated null effects on children’s development and language. An analysis of program materials suggests four reasons why the program may not have had the desired effects.