A sample of 60 children in Grade 3 was followed over one year. In the first year, an extensive battery of assessments was used including aspects of reading, arithmetic, and working memory. Teachers rated the children on 7-point scales on various motivational dimensions summarized to a total score tentatively called task orientation. In the follow-up assessment one year later, the testing and teacher ratings were repeated. The cross-sectional correlations between reading, arithmetic, and task orientation were all high (about +0.70). The high correlation between reading and arithmetic decreased significantly when task orientation was partialed out, and it was further reduced when working memory as assessed by backward digit span was added to the controlling factors. Also, teacher ratings of cognitive ability and language development accounted for some of the common variance between reading and arithmetic. The correlation between task orientation and school achievement cannot be causally interpreted in cross-sectional designs. Some support for a "causal" hypothesis, however, was obtained in crosslagged correlation analyses indicating that task orientation in Grade 3 may have a causal impact on the level of performance in reading, and in arithmetic in Grade 4. Most likely, however, there is also a reciprocal relationship. (Contains 2 tables and 1 figure.)