Purpose: Achievement motivation theory supports that one's perceived physical competence (PPC) is a predictor of their actual competence (Harter, 1999). However, Goodway and Rudisill (1997) found that children who are at-risk of developmental delays demonstrated low levels of motor skill competence (MSC) while reporting high perceptions of PPC. Recent studies have found that children who are at-risk of poor health also demonstrate poor MSC (Robinson, 2007; Robinson & Goodway, in press) and low PPC (Robinson, Rudisill, & Goodway, in press). The purpose of this investigation was to examine the relationship between PPC and MSC in 117 (54 girls and 63 boys) preschoolers who are at-risk of poor health. This investigation also determined the effect of sex on self-perception and motor skill ability in preschoolers. Methods: Participants actual MSC was assessed using the Test of Gross Motor Development – 2nd Edition (Ulrich, 2000) and PPC was assessed with Harter and Pike's (1984) Pictorial Scale of Perceived Competence and Social Acceptance for preschool- and kindergarten-age children. Analysis/Results: Participants mean scores for the TGMD-2 total, locomotor skill, and object control skill were 29.39, 15.73, and 13.67, accordingly. The preschoolers' reported a mean of 2.5 out of 4.0 on their PPC. Four separate analysis of variance were conducted to determine sex differences. The findings confirmed that sex differences were present for: a) TGMD-2 total score (p < .001), b) object control skills (p < .001), c) locomotor skills (p = .002), and d) PPC (p < .001). Boys' actual MSC and their perception of PPC surpassed that of the girls. In other words, boys demonstrated and perceived themselves to be more proficient. To determine the relationship among PPC, MSC, and sex, three separate stepwise regressions were conducted and revealed that object control skills (p < .001) alone and in conjunction with sex (p = .005) significantly account for variance in preschoolers' PPC. Locomotor skills proficiency (p < .001) and sex (p < .001) accounted for PPC. The preschoolers' TGMD-2 total score (p < .001) and in combination with sex (p = .003) contributed to PPC. Conclusions: Findings support that preschoolers' actual MSC and sex contributes to their PPC, and contradicts previous findings (Goodway & Rudisill, 1997). Keyword(s): early childhood, motor skills, physical education PK-12