The purpose of this inquiry was to examine the interrelations among handwriting legibility and speed, and underlying perceptual-motor skills in Persian language students. Seventy students (26 male, 44 female; 10.21 ± 1.02 yr; 30 poor and 40 good control hand writers) were assessed during a copying task. The children completed the visual-motor control (VMC), upper-limb speed and dexterity (ULSD), ‎ and upper-limb coordination (ULC) ‎ subtests of the Bruininks–Oseretsky test of motor proficiency (BOT). The poor group scored significantly lower on handwriting legibility and speed in comparison with classroom controls in the copying task. Correlation coefficients between perceptual-motor function scores with handwriting legibility, and with handwriting speed varied from -0.11 to 0.40, and 0.17 to 0.39 respectively. Results showed that both legibility and speed predicted differences between students classified as “poor” and “good” hand writers. Results also showed that in the poor hand writers group, age, gender, BOT-ULC, and BOT-VMC were found to be significant predictors of legibility of handwriting, whereas gender and BOT-ULC were shown to be significant predictors of handwriting speed. The findings suggest that distinct perceptual-motor components may underlie writing during copying. Poor quality of handwriting of children seems to be particularly related to some sort of deficiency and dysfunction in perceptual-motor skills. Future studies should determine the possible benefit of interventions including stimulant in perceptual-motor functioning and handwriting performance, to enhance performance in these areas.