This study examined the relationship between ninth-grade students' use of connectives (temporal, causal, adversative, and additive) in functional writing and performance on standards-based/criterion-referenced measures of reading and writing. Specifically, structural equation modeling (SEM) techniques were used to examine the relationship between students' use of connectives in their functional writing and their reading and writing proficiency. Results indicated that the number of connectives used in functional writing was significantly correlated to writing test scores and reading comprehension test scores, no matter whether the effect of the common predictor was removed or not. The results provide support for future research in the study of connective words in relation to functional writing skills and reading comprehension.