The purpose of this study was to examine the interrater and test-retest reliability of a one-leg balance test and a tiltboard balance test. Twenty-four normally developing children aged 4 through 9 years participated in the study. Time and quality of balance on one leg and degrees of tilt on a tiltboard prior to postural adjustment were measured. Both tests were completed with eyes open and with eyes closed. Interrater reliability was examined using two raters. Test-retest reliability, with a one-week interval between test and retest, was examined for a subgroup consisting of 12 children. Spearman rank-order correlation coefficients were used as indexes of both interrater and test-retest reliability for time and degrees of tilt. To supplement the correlation coefficients, the magnitudes of difference between raters' scores and between test and retest scores were calculated. Spearman coefficients were moderate to high for one-leg balance when scores for both feet were combined for both eyes-open and eyes-closed conditions. The magnitude of difference between scores was low, indicating good agreement between raters and across time. Interrater and test-retest reliabilities of quality of one-leg standing balance were examined by calculating percentages of agreement and Cohen's Kappa statistics. Results of these analyses revealed the need for further study. The Spearman coefficients for the interrater tiltboard test were high; however, the test-retest coefficients were low. The magnitudes of difference between scores were small for the two raters, but large for test and retest. These results are important to consider when using these tests for initial evaluation or for monitoring patient progress.