The applicability of Porter's commitment model was tested among two employee levels in a manufacturing and service company. Data were obtained from supervisory and shopfloor employees using a structured questionnaire. The findings indicate that the model is moderately adequate in predicting commitment among both levels of respondents in the two organizations, but the antecedents differ among respondents within and between organizations. Second, the commitment-outcome component of the model is only applicable to the service company in predicting performance, turnover intentions, and extra-role behaviors but not to the manufacturing company (except extra-role behaviors of shopfloor respondents). It is suggested that managers who wish to enhance the behavioral outcomes of commitment should first test the applicability of the model to their specific organizations.