The attitudes and beliefs that students hold about the subject of mathematics and about themselves as learners of mathematics contribute as much to the school's mathematical environment as do the concrete and cognitive aspects of mathematics. This paper considers the effects of mathematical affect and the use of intervention programs to increase the retention of women and minorities in higher-level mathematics courses. Mathematical affect plays a role in the development of long-term mathematical persistence behaviors, such as course-enrollment decisions. The most critical period in which to use interventions to influence mathematical affect is the middle/junior high school age level. More students will be able to develop the short-term persistence behaviors necessary to experience success within the mathematical environment when attention to affect begins to be included as a regular part of the mathematics curriculum. Once students possess short-term persistence behaviors, it will be easier to motivate them to continue to enroll in mathematics courses. (YP)