This article examined the relationship between participation in adult nonformal education (NFE), defined as on-the-job training, attending private lessons, attending seminars, or distance learning, and Canadian immigrant respondents' literacy and numeracy outcomes, using data from the Program for the International Assessment of Adult Competencies Survey. We found that although participation in some forms of NFE was significantly related to higher literacy and numeracy scores, such relationship tended to be greater for first-generation immigrants than for nonimmigrant adults, even after controlling for their linguistic and formal educational background. Our findings suggested that first-generation immigrants in Canada might benefit the most from increased participation in NFE programs and targeted policies.