The recent declines in membership suffered by most large, theologically “liberal” denominations and the continued growth of conservative and sectarian Protestant bodies provide the background for this investigation of denominational switching. Previous studies of switching were examined and found to either have methodological problems which made their conclusions about switching and denominational growth highly suspect, or they focused on other issues. It was hypothesized that the conservative denominations would be more healthy in terms of the three aspects of switching: stability, net gains, and the quality of converts. These hypotheses were then examined through a merged file composed of the 1973–1977 NORC General Social Surveys and the results indicate a more complex pattern than was initially expected. First, an advantage in only one aspect of switching may not lead to membership growth; and second, the growth of the conservative mainline denominations is very different from the growth of the conservative sects.