Motor competence as an indicator of gross motor development is characterized by changes in movement patterns and outcomes. The Test of Gross Motor Development-3 consists of six locomotor and seven ball tasks used to assess the quality of fundamental motor skills in children. The purpose of this study is twofold--to produce a Slovenian translation of Test of Gross Motor Development-3 and to evaluate it on a sample of Slovenian children. First, a back translation was carried out with the help of relevant field professionals, thus producing a Slovenian version of Test of Gross Motor Development-3 with excellent content validity. Second, trained assessors rated the video-recorded test tasks of 452 Slovenian children with smaller groups of measured participants repeating the procedure within 2- and 4-week interval to assess reliability. Finally, the collected data were analyzed using several statistical methods. The data showed good to excellent reliability for intrarater, interrater, test-retest reliability, structural validity, and internal consistency for the majority of motor skills, as well as good measurement invariance across genders.