The aim of this study was to contribute to our knowledge of the construct validity of the Griffiths Scales of Mental Development (Griffiths Scales) through an examination of the underlying dimensions tapped by the six subscales, using Common Factor Analysis. A sample of 430 South African children, from four ethnic groups (i. e. White, Mixed Race, Asian and Black) participated. The correlation coefficients obtained for the South African groups were compared to those Griffiths obtained in her work with the British standardization sample of the Griffiths Scales. The pattern of correlation for South African and British subjects was found to be similar. This suggests that the Scales are measuring a construct which is consistent across cultures and through time. A factor analysis was performed with the data for each South African ethnic group separately and the factor solutions were compared to determine whether the Griffiths Scales measure similar or different constructs for the groups. The results indicate that the Griffiths Scales tend to measure one factor, and including only common variables, the factor appears to be similar cross-culturally.