Although mental health needs may be similar among CalWORKs recipients regardless of acculturation, substance-related problems may be less frequent among Spanish-speaking Latinas participating in the CalWORKs program. Low acculturation was not a significant predictor of mental health need but had a protective effect with regard to substance-problem risk after controlling for several other substance-problem risk variables. Research on mental health and drug use among Latinos/Latinas in the general population has found that higher acculturation is a risk factor for psychiatric and substance use problems. However, few studies have focused specifically on mental health and substance use-problems among low acculturated Latinas in the welfare population. This analysis contributes to the literature on the relationship between acculturation and mental health and substance use in several ways. The study tested the potential protective effects of low acculturation, defined as Spanish language use, with regard to psychiatric symptoms and substance problem risk among Latina applicants or recipients of CalWORKs’ benefits. Four hypotheses were tested with support found for two of the four. Tables and references