In the present paper, we attempt to explore the relationship between the subject's religious involvement degree and his Work Centrality (WC) or the importance of working in his whole life. A total of 345 Muslims, living in Japan, were surveyed. To measure the religious involvement, we constructed three different scales that were combined at the individual level to obtain a Religious Index (RINDEX). Based on the RINDEX score, the subjects were divided into HRINDEX (High RINDEX; high involvement with Islamic Religion), MRINDEX (Moderate RINDEX; moderate involvement with Islamic Religion) and LRINDEX (Low RINDEX; low involvement with Islamic Religion) subsamples. To measure the work centrality level we also used two differents measures that were combined to have a general index that is supposed to indicate the subject's degree of importance attached to work. As hypothesized, the results indicated that the HRINDEX subjects were more likely to have a higher WC than do both the MRINDEX and LRINDEX subjects. The results of this study support the general hypothesis that links the subject's belief or value to his/her attitudes.