Researchers studied components of a two-year school-wide Striving Readers intervention aimed at bolstering middle school teachers' use of literacy strategies to raise students' reading achievement. Although students of intervention teachers had significantly higher Iowa Test of Basic Skills (ITBS) scores than students of non-participating teachers, no evidence was found that suggested relationships existed among teachers' fidelity of implementation (FOI), observed cognitive demand level of classroom lessons, and students' performance on the ITBS. Higher cognitive demand and FOI ratings were associated with use of more literacy strategies overall, and comprehension strategies in particular. Study implications, limitations and areas for future research are discussed. (Contains 4 tables.)