The purpose of this study was to examine slopes from curriculum-based measures of writing (CBM-W) as indicators of growth in writing. Responses to story prompts administered for 5 min to 89 students in Grades 2-5 were collected across 12 weeks and scored for correct word sequences (CWS) and correct minus incorrect sequences (CIWS). Linear mixed modeling revealed that, for students in Grades 2-3, a linear model with random effects on both intercept and slope fit the data best. For students in Grades 4-5, growth trends varied depending on number of weeks and scoring procedure used. The time point at which slopes were significantly different from zero varied by scoring procedure and grade. Gender was related to intercept and slope for CWS and CIWS in Grades 2-3 and to intercept and linear slope for CWS and CIWS in Grades 4-5. Findings suggest that CBM-W may be appropriate for monitoring student progress, and that gender should be considered in data-based decision making.