Difficulty with handwriting is one of the most frequent reasons that children in the public schools are referred to occupational therapy. Current research on the influence of ergonomic factors, such as pencil grip and pressure, and perceptual–motor factors traditionally believed to affect handwriting, is reviewed. Factors such as visual perception show little relationship to handwriting, whereas tactile–kinesthetic, visual–motor, and motor planning appear to be more closely related to handwriting. By better understanding the ergonomic and perceptual–motor factors that contribute to and influence handwriting, therapists will be better able to design rationally based intervention programs.