Immigrant families with children with developmental disabilities must be served using culturally sensitive approaches to service and research to maximize treatment benefits. In an effort to better understand cultural issues relevant to the provision of parenting programs for immigrant Mexican mothers of children with developmental disabilities, we conducted sustained focus groups through which we could learn more about our participants and thereby improve services. This paper reports on the challenges and lessons learned from these groups. We characterize the key lessons as (a) recruitment and retention is more than agreement to participate; (b) confidentiality is not just a word but an activity; (c) the complicated nature of language; (d) cultural norms shape the group process; (e) appreciating the value of taking time; and (f) gender issues and group interaction. Service providers and researchers who work with Mexican families may benefit from our experiences as they promote and develop programs and projects in the developmental disabilities field.