This study of the effectiveness of transitional bilingual education (TBE) programs for Hispanic students in five Massachusetts school districts analyzed data on students' personal and educational characteristics (place of birth, socioeconomic status, number of years in TBE, district mobility, attendance, test scores, academic grades, and remediation). The student sample was comprised of 214 students in grades 1 through 12 and included TBE students, mainstream students who had previously been in TBE, and limited-English-proficient (LEP) students never enrolled in TBE. The major findings were: (1) the average time in TBE, current or previous, was about three years, with 9 percent in TBE more than three years; (2) although the majority of the students had attended schools only in their district, one third had attended at least three schools there, and one third had attended schools in their native countries; (3) the current TBE students had lower attendance than the mainstream students but higher attendance than non-TBE LEP students; (4) over 90 percent of the TBE and mainstream students had C averages or higher, while 42 percent of the non-TBE LEP students were failing; (5) several times as many non-TBE LEP students as others had repeated grades; and (6) although only 9 percent of the TBE students had been referred for special education, 12 percent of the mainstream and 26 percent of the non-TBE LEP students had been referred. (MSE)