The assessment of multiliterate handwriting performance is rarely reported despite increased globalization. The present study describes the psychometric properties of a handwriting speed test developed for children who are biliterate in English and Chinese. This included interrater reliability, test-retest reliability, interitem correlation, construct validity, and concurrent validity. The test's reliabilities between two raters and over a 1-wk. interval were high with ICCs ranging from .89 to .99. Interitem correlation between the English and Chinese items was .87. The presence of age trends but not sex differences was a positive indicator of the test's validity. Correlations of .91 and 1.00 between the Chinese and the English items of the Handwriting Assessment Tool with the Chinese Handwriting Speed Test and Handwriting Speed Test, respectively, provided evidence of concurrent validity. These preliminary results showed the Handwriting Assessment Tool is reliable and is a potentially useful handwriting test for children biliterate in English and Chinese. The feasibility of assessing biliterate handwriting speed performance with the same set of scoring criteria for different writing systems was supported.