The study aimed to examine the relationship between morphological knowledge and reading comprehension ability among college-level English as a foreign language (EFL) students. One hundred and twenty-one students participated in this study and they completed two morphological knowledge measures (morpheme-form knowledge and morpheme-meaning knowledge), reading vocabulary knowledge, lexical inference and reading comprehension. Drawing upon hierarchical regression and path analysis, the study found that morphological knowledge explained a unique proportion of variance in reading comprehension after word-meaning knowledge was accounted for. In addition, morphological knowledge had direct and indirect effects on EFL reading comprehension via reading vocabulary breadth and lexical inference ability. To be more specific, the mediating effect of morpheme-meaning knowledge seemed to be salient in EFL reading comprehension. Conceptual and methodological interpretations were discussed based on the findings.