The correlation between scores on the Columbia Mental Maturity Scale and on the McCarthy scales was calculated for 68 kindergarten children from three nursery schools in a lower-class urban area. Analysis indicated significant correlations for the Columbia Mental Maturity Scale with Perceptual-Performance, Quantitative, Motor Scales and General Cognitive Index and negligible values (.14 to .15) between Columbia scale and McCarthy Verbal and Memory subscales. The implications are discussed.