Previous programs had not designed the culturally adequate Lay Health Advisor (LHA) oral health training curriculum for medically underserved population. We evaluated the effects of LHA training curriculum for addressing immigrant children's caries disparities in their access to dental care. We used a pre/post-test study design. Immigrant women were recruited from churches, schools, and immigrant centers in an urban area. Four training classes were held. Each training cycle lasted 15 consecutive weeks, consisting of 1 weekly 2-h training session for 12 weeks followed by a 3-week practicum. The curriculum included training in caries-related knowledge, oral hygiene demonstrations, teaching techniques, communication skills, and hands-on practice sessions. Thirty-seven LHA trainees completed the course and passed the post-training exam. The data were collected using self-report questionnaires. The level of oral health knowledge, self-efficacy and attitudes toward oral hygiene were significantly increased after LHA training. There was a significant and over twofold increase in trainees' oral hygiene behaviors. An increase of >20% in LHA and their children's dental checkup was observed following training. After training, LHAs were more likely to have 3+ times of brushing teeth [Odds Ratio (OR) = 13.14], brushing teeth 3+ minutes (OR = 3.47), modified bass method use (OR = 30.60), dental flossing (OR = 4.56), fluoride toothpaste use (OR = 5.63) and child's dental visit (OR = 3.57). The cross-cultural training curriculum designed for immigrant women serving as LHAs was effective in improvement of oral hygiene behaviors and access to dental care.