AN EXPERIMENTAL CLASS IN BICULTURAL AND BILINGUAL EDUCATION WAS CONDUCTED FOR THE CHILDREN OF MEXICAN DESCENT IN MARYSVILLE, CALIFORNIA. THE CLASS, PLANNED ON AN UNGRADED BASIS, INCLUDED 8 BOYS AND 11 GIRLS WHOSE AGES RANGED FROM 6 TO 10 YEARS AND WHOSE GRADE PLACEMENTS ORDINARILY WOULD HAVE BEEN FROM KINDERGARTEN TO GRADE 4. TWELVE OF THE 19 SPOKE BOTH SPANISH AND ENGLISH, AND 6 PUPILS SPOKE AND UNDERSTOOD ONLY SPANISH. THE CURRICULUM WAS DESIGNED SO THAT THE CONTENT AREAS IN ARITHMETIC, HISTORY, GEOGRAPHY, AND SCIENCE WERE ADAPTED IN SPANISH TO PROMOTE THE ACQUISITION OF THE NECESSARY CONCEPTS, AS THE PUPILS USED THEIR NATIVE LANGUAGE TO MEDIATE LEARNING. THOUGH THE PARENTS, TEACHERS, AND PUPILS SEEM VERY POSITIVE IN THEIR ATTITUDES TOWARD A BILINGUAL PROGRAM OF INSTRUCTION AND MANY PUPILS DID EXPERIENCE SUCCESS, CONCLUSIVE EVIDENCE OF THE EFFECTIVENESS OF BILINGUAL CLASSES IS NOT AVAILABLE BECAUSE A CONTROL GROUP WAS NOT UTILIZED. (ES)