Generally, the levels of participation and achievement of females in science do not match those of male learners. This report describes the formation and study of an all-female section of calculus-based physics for the purpose of providing an environment that might enhance the participation and achievement of females in the physical sciences so that the Illinois Mathematics and Science Academy could study the phenomenon of disproportionately low participation and achievement of females in an upper-level physics course. The study employed a pretest-posttest experimental-control group design and included three co-ed sections and one all-female section of first semester calculus-based physics. Findings included: (1) a different quality to the atmosphere, character, and climate of the all-female class; (2) greater performance-level growth on quizzes, homework, and class exams of students in the all-female class; (3) more females enrolled in and successfully completed calculus-based physics than before; (4) females in the all-female section demonstrated a significantly higher growth in self-confidence; and (5) for students who participated in the experimental section, prior facility in mathematics was less important for subsequent achievement success. (Contains 35 references.) (MKR)