Introduction: This study examined health-related information needs, seeking, and source preferences between two distinct groups of mothers--U.S. mothers and immigrant Korean mothers in the U.S.A. Method: Using non-probability sampling, data were collected from five online communities through an online survey; 480 completed responses were used for analysis. Analysis: Both quantitative (using SPSS) and qualitative analyses (with Nvivo 11) were implemented in analysing the collected data. Results: Although the participants were mothers of young healthy children, the topic they searched for most frequently was information about diseases. Moreover, 93.0% of the U.S. mothers and 94.2% of immigrant Korean mothers had searched for health information in the past six months. When source preferences were compared, U.S. mothers preferred human sources (e.g. doctors, nurses, their husband and other relatives), whereas immigrant Korean mothers preferred non-human sources (e.g. online communities, books). Conclusion: Findings confirm that mothers actively search for health-related information as part of their roles as caregivers or health managers for their children. Results also imply that appropriate use of a few social media platforms has great potential for information professionals who provide health-related information to mothers with high information needs.