The present study was designed to identify the quality dimensions as perceived by adult learners who had taken one or more e-learning courses offered by higher education institutions in South Korea and to identify and confirm the structural features of these quality dimensions. The results of the exploratory factor analysis arising from a survey of 299 learners revealed that from their perspective, there were seven dimensions in evaluating the e-learning quality: "Interaction," "Staff Support," "Institutional Quality Assurance Mechanism," "Institutional Credibility," "Learner Support," "Information and Publicity" and "Learning Tasks." And the confirmatory factor analysis with responses obtained from another set of 496 adult learners confirmed a good fit of the seven-factor model to the observed data. While most of these seven dimensions are supported by previous studies, some dimensions, such as technology support, content and evaluation/assessment that e-learning providers had highlighted did not appear to be important for Korean adult learners. Possible explanations for these findings are discussed in relation to learner characteristics, e-learning design, and culture, and further research topics are suggested.