This study examined information technology professionals' perception of employee organizational commitment (OC) and its relationships to turnover across various industries in Thailand. Perceived job alternatives and thoughts of quitting were included to examine their influence on turnover intention both directly as independent variables and indirectly as mediators. Hypotheses tested were 1) the direct relationship between organizational commitment and turnover intention among IT personnel from various Thai companies, 2) the relationship between thoughts of quitting and turnover intention, 3) the relationship between perceived job alternatives and turnover intention, 4) the indirect relationship between organizational commitment and turnover intention through mediator - thoughts of quitting and 5) the indirect relationship between organizational commitment and turnover intention, as mediated by perceived job alternatives. The survey questionnaire used instruments that were already translated into Thai from previous research (Wongrattanapassorn, 2000). The original items in English were included with each item in the Thai language to provide respondents with additional information on the meaning of constructs. In addition to demographic items, the survey questionnaire contained four measures, one for each of the four variables: organization commitment (Allen & Meyer, 1990), thoughts of quitting (Peters, Jakofsky & Salter, 1981), perceived job alternatives (Peters, et al., 1981), and turnover intention (Hom, Griffeth & Sellaro, 1984). An accompanying letter with the hyperlink to the questionnaire page was sent via e-mail to 300 IT professionals who were randomly selected from the subscribers of Computerworld Thailand magazine and also those who attended IT seminars organized by Computerworld Thailand. Two hundred and eight responses returned, providing an acceptable response rate of 69.3 percent. Correlation and regression were used to test hypotheses. Results revealed that there was no direct relationship between overall organizational commitment and turnover intention. However, there was a negative direct relationship between continuance commitment and turnover intention. There was also no correlation between thoughts of quitting and turnover intention. There was a positive relationship between perceived job alternatives and turnover intention. For the mediating effect between organizational commitment and turnover intention, the results revealed that thoughts of quitting did not mediate the relationship as well as perceived job alternatives.