The purpose of this study was to examine the validity and reliability of Curriculum-Based Measures in writing for English learners. Participants were 36 high school English learners with moderate to high levels of English language proficiency. Predictor variables were type of writing prompt (picture, narrative, and expository), time (3, 5, and 7 min), and scoring procedure (words written, words spelled correctly, correct word sequences, correct minus incorrect word sequences). Criterion variables were teacher ratings of writing performance and student performance on the Test of Written Language-III, the writing subtest of the Test of Emerging Academic English, and the Minnesota state writing test. Results supported the validity and reliability of a 5 to 7-min writing sample written in response to a narrative or picture prompt and scored for percent of correct word sequences, correct minus incorrect word sequences, or words written plus correct minus incorrect word sequences.