The purpose of this research is to examine the relationship between religious, demographic, Socio-economic and community organizational factors influencing the fertility control of Buddhist and Islamic women. Data was obtained from the Third Round of Contraceptive Prevalence Surveys Conducted by The Institute for Population and Social Research, Mahidol University, Research Center of The National Institute of Development Administrative and Division of Family Health, Ministry of Public Health. Research samples include 1,516 married women aged 15-49 years-old in Southern Thailand and who are either Buddhist or Islamic.Data were analyzed using Chi-square, Pearson Product Moment Correlation and Regression and Regression Analysis techniques. Findings from the Chi-square test indicate that for Buddhist woman all factors relate significantly to the use of fertility control. For Islanmic women only age, number of living children, desire for children, educational level and the location of fertility control service obtainment related significantly to contraceptive use. Marital status and occupation were not significant. For Pearson Correlation analysis, the most significant factors relating to the contracelptive use is religion. Regression analysis reveal that when factors associated with demographic, socio-economic and community organization are controlled, religion still positively influences fertility control usage. Factors of subsidiary importance include desire for children, level of education, age, number of living children and occupation (i.e., agriculture), in descending order of significance.