ABSTRACTSpay/neuter (S/N) programs aim to reduce shelter intake and euthanasia. However, there is little published evidence of a causal effect between S/N programs and shelter intake or euthanasia. To uncover any ancillary effects of S/N, this study examined the impact of S/N door-to-door outreach on welfare-related outcomes and attitudes around S/N in underserved areas of New York City. There was no significant difference between a group receiving intensive outreach and a comparison group on whether they had rehomed a companion animal in the last year. There was a significantly higher level of saturation of S/N in the intensive-outreach area. A significantly higher percentage of those in the intensive-outreach group reported knowing at least 1 way to get help for their companion animals and that the caregiver-defined general well being of nonhuman animals in their neighborhood was better during the previous year. These data suggest that intensive S/N outreach has an impact on the level of saturation of S/N, the perceived efficacy of caregivers to find help if needed, and the perception that animal welfare is being improved.