A study was undertaken to verify reliability of both the new computer tests of manual dexterity and known dynamometric and Nine-Hole Peg tests in two groups of 84 (average age 10.5 ± 2.4) and 61 (average age 11.02 ± 2.45) children aged from 7 to 15, respectively. In these groups the series of measurements was twice repeated. A detailed statistical analysis of the results was made and indices describing reliability of the tests were determined. Correlation coefficients between the tests performance in the first and second series of measurements (at a week distance) by children from the same group were calculated proving a high and statistically significant correlation between the measurements. A comparison of the Pearson's coefficients calculated from our data with corresponding values for the tests known from literature proved a very good agreement. In addition, to check the computer tests stability, the statistical significance of differences between the average values of times of the tests completion in the two series, was analysed.