Handwriting difficulties affect 10% to 30% of children in elementary school often hindering their successful participation in a number of occupations, including academic participation. Occupational therapists provide treatments for handwriting difficulties; however, many of these interventions have limited to no evidence to support their effectiveness. One of these interventions is the use of a slant board, a treatment strategy often combined with handwriting practice. Clinicians commonly combine the use of slant boards and handwriting practice to facilitate the development of handwriting skills in young children. However, the effectiveness of this combination of interventions in improving the quality of handwriting remains unclear. The aim of this study was to investigate the difference in the change of letter formation scores in children who have practiced handwriting on slant boards compared with those who have practiced on a horizontal surface. A randomized block design was employed. Children entering the second through third grades who participated in a 19-day summer enrichment program were recruited via mailed recruitment letters and/or email. Twenty-one children were enrolled. Children were blocked by classroom and randomly assigned to a group that practiced handwriting on a slant board or a group that practiced on a horizontal surface. Children completed a total of 15 group sessions lasting 15 minutes each. These sessions occurred 3 to 5 days a week over the course of 4 weeks. During these sessions, they practiced writing letters and words utilizing the Handwriting Without Tears curriculum. There was no significant difference in average group change in letter formation performance as determined by independent samples t test. Children with below average handwriting at baseline made statistically significant changes in their handwriting, regardless of writing surface, when compared with their peers that was identified by secondary analyses.