The purpose of this study was to examine the technical features of slopes produced from the curriculum-based measurement in writing (CBM-W) word dictation task. Seventy-nine elementary students in the U.S. Midwest with intensive learning needs responded to weekly word dictation probes across 20 weeks; responses were scored for correct letter sequences (CLS). Scores showed evidence of high reliability and sensitivity to growth in a short period. Linear mixed modeling revealed that students gained an average of 0.91 CLS for each additional week of instruction. Initial writing levels and growth rates did not significantly differ depending on students' demographic characteristics. Based on these findings, we illustrate how word dictation slopes can be used as indicators of writing growth for students with intensive learning needs.