Objective: To test the mechanisms by which exposure to point-of-sale (POS) e-cigarette marketing mediate the relationship between an ethnic minority group highly vulnerable for tobacco product use, namely Native Hawaiian/Other Pacific Islander (NHPI), and increased future e-cigarette use through explicit (positive outcome expectancies) and implicit (spontaneous positive reactions) pathways. Method: Four waves of data were collected in 6-month intervals from 2,327 multiethnic young adults (Mage = 21.2, SD = 2.2; 54% women) enrolled across two 4-year and four 2-year colleges belonging to a University system in Hawaii. POS e-cigarette marketing exposure was assessed with an objective measure involving store visit patterns and store audits, as well as a measure of self-reported exposure. Spontaneous reactions were assessed with an implicit measure, namely Affect Misattribution Procedure (AMP). Path analyses were used to test the hypotheses. Results: In a model employing the objective measure of POS exposure, a statistically significant pathway was found from NHPI ethnicity to increased current e-cigarette use at Wave 4 mediated through increased POS exposure at Wave 2, and increased affect regulation expectancies at Wave 3. Similar indirect effects on prospective e-cigarette use were found for Asian ethnicity. The dual process model of the effects of POS exposure on e-cigarette use was not fully supported, although the implicit measure was found to independently predict e-cigarette use. Conclusions: Differential exposure to POS marketing may explain some of the ethnic disparities in tobacco product use behavior such as e-cigarette use. POS marketing may affect e-cigarette use behavior mainly through the explicit pathway, notably affect regulation expectancies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).