As part of a larger study of significant bilingual instructional education features, the stability of instruction by 10 teachers was examined. Six aspects of instruction were investigated: instructional organization, time allocation, active teaching, use of the students' native or English language and culture, curriculum intent, and the teacher's sense of efficacy. Ten case studies and analysis across cases revealed that (1) teachers were least consistent in their organization of learning activities, possibly due in part to changes of district policy and teaching assignment; (2) the trend was toward more instruction in reading and language arts; (3) teachers' use of English language materials increased and use of native language materials decreased during a portion of the study; (4) observer ratings of teacher performance were higher during the second part of the study; (5) teachers increased use of English and decreased use of the students' native language; (6) the teachers' pattern of language alternation was fairly stable; (7) teachers tended to stress language alternation for instructional development as they increased their oral use of English, allocated more instructional time to reading and language arts, and became more clearly focused on academic matters; and (8) curriculum intent and sense of efficacy appeared stable. (MSE)