Objectives: Handwriting is a work activity for children, hence it may be evaluated based on ergonomic factors. This study investigated whether nonproficient handwriters could be distinguished by biomechanical ergonomic factors during handwriting, as well as by measures of handwriting efficiency. Furthermore, the relationships among ergonomic factors, handwriting quality, efficiency, and measures of the handwriting process were examined., Methods: Fifty proficient and 50 nonproficient third-grade handwriters performed a handwriting task on an electronic tablet. Biomechanical ergonomic factors, measures of handwriting quality, and efficiency were rated using the Hebrew Handwriting Evaluation. Handwriting process measures were obtained from a computerized system., Results: Biomechanical ergonomic factors and handwriting efficiency measures significantly differentiated between the study groups. Significant correlations were found among ergonomic factors and handwriting quality, efficiency, and process measures., Conclusion: Nonproficient handwriting is a work activity that is often characterized by inferior biomechanical ergonomics, handwriting quality, efficiency, and significantly different handwriting process measures. Results provide insights that can assist in planning intervention.