This report describes a 9-month project, conducted in seven states, during which teaching strategies and teacher attitudes which successfully encouraged girls in science were observed, described, and analyzed. Biology, taken by over 80 percent of high school students, was the course selected for observation; if girls are turned off to science in biology, they effectively close the doors to scientific or technological careers. Following a brief introduction, eight case studies of teachers who have had a "track record" of success with young women in science are presented. Authors of these studies are Exyie Ryder, Jane Butler Kahle, Ann Haley-Oliphant, Julia Riggs, Frances Vanderdoort, Jane Abbott, Joseph McInerney, and Elizabeth Stage. A summary is also provided in which data collected at all the case study schools is analyzed, case study sites and teachers compared and contrasted, and general conclusions drawn. Several behaviors of teachers who are successful in encouraging girls to pursue science were found. They include: (1) providing career information and informal academic counseling; (2) demonstrating unisex treatment in science classrooms; and (3) not using sexist humor and not allowing boys to dominate discussions or activities. (JN)