Instruction in fundamental movement skills (FMS) is central to most elementary physical education curricula. And with good reason: Not only do FMS's form the basis of further sports skill development, their mastery contributes substantially to peer acceptance and approval. Moreover, FMS's provide children the tools with which to remain active and physically fit--a major societal concern. Given the importance of FMS's to child development, current data is needed upon which to base effective instruction. The purpose of this study was to examine children's (ages 5- 14, grades k-8, N=186) performance on four key object control skills. The design of this study was cross-sectional correlational. We tested all children on the catching, throwing, kicking, and striking items of the Test of Gross Motor Development-2 (TGMD-2). Prior to testing in September, we conducted a pilot study to establish inter-rater reliability. A reliability coefficient >.90 was achieved by two independent raters for each component of the four object control skills. Following testing, we ran multiple regression analyses with TGMD-2 score for each skill as the criterion variable; and age, sex, and age-sex interaction as the independent variables. As anticipated, we observed significant (p< .001) improvement by age on all four skills. A visual inspection of the graphed data revealed early, rapid improvement, with most gains achieved by age 9 or 10; after which, development of the four skills plateaued. We found no sex differences in catching. However, we observed sex differences favoring boys in throwing, kicking, and striking (p<.05). We also noted signifcant (p<.05) age-sex interactions in catching, kicking, and striking. These interactions followed no discernible pattern and may indicate cohort effects associated with our cross-sectional sample. We reached the following tentative conclusions: a) Sex differences, favoring boys, may still exist in key object control skills; and b) development of catching, throwing, kicking, and striking appears to peak at ages 9-10 with little additional improvement for some children by age 14. It is therefore recommended that physical educators carefully monitor children's object control skills in the early grades; with the goal of all children achieving mature patterns before they enter the next level. Children who progress to the upper grades without an adequate foundation of FMS's will have fewer opportunities to develop sports skills. To address potential cohort effects, further investigations might employ longitudinal designs with multiple birth-cohorts. Keyword(s): motor skills, physical education PK-12, research