Dependable parent reports of infant gross motor milestones would be useful for many purposes. This paper reports on the development of a parent checklist related to sitting, crawling, and walking. Ninety-five mothers of infants completed the checklists daily and returned them monthly. Assessors visited the infants (2.5 to 15.7 months of age) at their homes and observed them using the Alberta Infant Motor Scale (AIMS). Some AIMS items corresponded in content with parent checklist items, so parent checklist reports during the week prior to the home visit were retrospectively validated against the assessor scoring of the AIMS items. Concordance for all comparisons was over 65%, and 11 of 12 comparisons had significant kappas, 7 of which were substantial to almost perfect. This suggests that parents can provide dependable reports of sitting, crawling, and walking milestone attainment.