The third year of the partial immersion program in grades one through three at Key Elementary School (Arlington, Virginia), where half the day is taught in English and half in Spanish, is reported. The review includes classroom observations, student and teacher interviews, student assessment, and parent and staff interviews. Student assessments were also undertaken so that progress could be measured in both Spanish and English (standardized tests, oral language assessments, and teacher evaluations). The Language Assessment Scales and the Boehm Test of Basic Concepts were used respectively for language proficiency and mastery of concepts. Achievement in social studies and science was above average, and all but one student read at or above grade level in both English and Spanish. Parental response was enthusiastic, and the program had become a model two-way immersion program that attracted international visitors. Reasons for the program's success are identified as the following: teacher/staff dedication; coordination between the two immersion classes and between the English and Spanish parts of the day; development; and the active involvement of parents. Three major recommendations are offered: (1) continue and expand the program to include grades 1-4; (2) attract a wide variety of students from all over Arlington; and (3) implement a long-term plan for the continuation of Spanish instruction for immersion students in middle and high school. Contains 2 references. (LB)