A study examined the relationship of multiple measures of reading and writing at the second and fifth grade levels. Multiple reading tests (measuring vocabulary, word recognition, sentence comprehension, and passage comprehension) and writing tests (evaluating vocabulary diversity and syntactic complexity, and providing qualitative and quantitative measures of spelling and organization) were administered to 256 second grade and 251 fifth grade students. The relationships of these variables were evaluated through the use of canonical correlational factor analysis, with separate analyses performed for each grade level cohort and for two additional cohorts--beginning readers and proficient readers--derived from the original grade level samples. These analyses indicated that the word recognition factors drawn from the reading set were most related to the spelling variables of the writing set at both grade levels. However, substantial differences were apparent across reading level cohorts. For beginning readers, again, the word recognition factor drawn from the reading set was most related to the spelling variables in the writing set. For the proficient readers, the ability to structure prose in complex ways and to use a variety of vocabulary in writing was related to a prose comprehension factor derived from the reading set. (Author/FL)