Only the questions related to birth control and contraceptive usage from the Rhode Island Health Survey completed in 1968 and 1969 a research study was conducted to compare past present and future use and types of contraceptives among Catholics and non-Catholics. Randomly selected female respondents numbering 367 Catholics and 148 non-Catholics once married under age 50 and living with their husbands were questioned on contraceptive usage. Results indicated that Catholics were almost as likely as non-Catholics to be users. However in regard to type of contraceptive only young Catholics preferred oral contraceptives over the rhythm method as the present and future method of choice. Otherwise the rhythm method remained the first choice of Catholics. Non-Catholics were overwhelmingly users of oral contraceptives although the diaphragm was very popular among older women. The finding that many Catholics were still loyal to less efficient birth control practices implies that their stated expected family size goals may be exceeded. Nevertheless evidence exists that convergence in fertility behavior between the two religious groups is beginning to emerge. This convergence may be completed in the near future if the expected plans of young Catholics remain unchanged and if the effect of Catholic teaching begins to diminish.