The introduction of the System of Multicultural Pluralistic Assessment's (SOMPA's) Sociocultural Scales potentially enables psychologists to more formally acquire and use information about sociocultural characteristics within children's families. However, until now, data on the Scale's stability have not been available. This paper reports the results of a longitudinal study which examines the stability of the Sociocultural Scales over a four year period. The 44 elementary school children studied were drawn from middle and lower class Anglo, Black and Mexican American families. Although some variance in scores is noted, the Sociocultural Scales generally are stable. The magnitude of change in individual and in mean scores is not large, and test-retest correlations are moderate to high. While actual changes in family conditions may have contributed to score variance, scores on items which should have been the same across administrations suggest that respondent or interviewer inconsistencies also may contribute to variance in scores. (Author)