In recognition of the vital role socio-cultural variables play in science classrooms, researchers are now beginning to call attention to, and encourage serious considerations of the socio- cultural background of pupils which affect their learning and understanding of science. An effective point to begin the empirical study of socio-cultural influences in science classrooms is the development of an instrument to identify these influences. This paper describes the development, revision, and validation of a 30-item, Likert-like instrument called the Socio-Cultural Environment Scale (SCES) to measure the socio-cultural environment of science classrooms in a non-western society. The instrument was developed after a content validation by science educators, sociologiests, science teachers, and anthropologists and was administered to a total of 707 grade 11 and 12 secondary school students to determine the internal consistency reliability and construct validity of the items. The SCES has a Chronbach alpha reliability of 0.92; inter-item correlations ranged from 0.48 to 0.96; and the intra-scale consistency for the five scales identified ranged from 0.70 to 0.98. Factor analysis of the data indicated that the items on the instrument clustered into social and cultural entities. The educational implications of this study are discussed. (Author/CW)