The Corsi Block-Tapping task has been utilized as a measure of spatial memory in both clinical and research contexts for several decades. Despite its wide application, the task has been employed with extraordinary variability in administration and scoring and in the composition of stimulus item sets. We have generated a set of test items containing quasi-randomly derived block-tapping sequences. In another study, we investigated item difficulty as a function of path configuration and showed a decline in performance with increasing span capacity load. In the current cross-sectional study, we evaluated developmental differences in span capacity by measuring performances of school children from grade 1 (M age = 7 years) to grade 8 (M age = 14) and a young adult sample (M age = 21 years). Mean span capacity increased incrementally and linearly with age, and no gender difference was observed. The increase in performance with advancing age supports the notion that spatial immediate memory capacity increases with maturation throughout childhood. Comparisons indicated that the span capacity of eighth graders (M = 6.9) was not statistically different from that of the young adults (M = 7.1), suggesting an upper developmental plateau for spatial span in early adolescence. This study provides a normative database for this widely utilized measure of spatial memory.