The 12 studies that constituted the 1971-1972 evaluation of the Let's Be Amigos program are presented together with the evaluation findings. The three components of the Bilingual Program, serving 1,813 students by the end of the third year, were the Model A program (prekindergarten to grade 3) with teams of English- and Spanish-speaking teachers working with the students; the Model B program (grades 1 and 2) in which teachers worked with students who were dominant in the teacher's mother tongue; and the ARRIBA program (elementary, junior high, and senior high schools) serving primarily Latino pupils who could benefit from instruction in their mother tongue. The evaluation studies were categorized as to Process Evaluation Studies (four studies) and Product Evaluation Studies (eight studies). The Process Evaluation Studies were: General Process Evaluation of the Third Year of the Bilingual Program; Perceptions of Prinicpals, Teachers, and Parents Regarding the Bilingual Program; Curriculum Development, Distribution, and Tryout in the ARRIBA Program; and Follow-up of Elementary-Level ARRIBA Pupils Who Moved into Regular English Language Classes. The Product Evaluation Studies were: Log of Pupil Performance in the Model A and Model B Programs; Criterion-Referent Testing of Second- and Third-Grade Arithmetic Skills in the Model School Program; Exploratory Testing of ARRIBA Junior High School Students; and Replication of Findings Assessing the ARRIBA Component's Impact on Elementary School Pupils' Attendance and High School Pupils' Dropout Rate. (DB)