The concurrent validity of a 1 minute walk test at a child's maximum walking speed was assessed in children with bilateral spastic cerebral palsy (BSCP). The distance covered during the 1 minute walk test was compared with the children's gross motor function as assessed by the Gross Motor Function Measure (GMFM). Twenty-four male and 10 female children with CP (mean age 11y, range 4 to 16y) participated in the study. Gross Motor Function Classification System (GMFCS) levels were; level I (n=3), level II (n=17), level III (n=10), and level IV (n=4). Participants had clinical diagnoses of symmetrical diplegia (n=19), asymmetrical diplegia (n=14), and quadriplegia (n=1). Results showed a significant correlation between GMFM score and the distance covered during the 1 minute walk (r=0.92; p<0.001). There was also a significant decrease in the distance walked with increasing GMFCS level (p<0.001). We concluded that the 1 minute walk test is a valid measure for assessing functional ability in children with ambulatory BSCP. Its cost-effectiveness and user friendliness make it a potentially useful tool in the clinical setting. Further study needs to address its reliability and ability to detect change over time.