Background: Research examining the relationship between reading skill and reading motivation has typically been carried out among children with a wide range of reading abilities. There is less research focusing on children who excel in reading or who are attaining very low reading scores. Purpose: To examine whether there were differences between children identified as excellent or very poor readers in the relationship between their levels of reading skill and intrinsic and extrinsic reading motivation. Sample: In total, 1811 children (aged seven to 13 years) were tested, with good readers (top 10%; n = 194) or poor readers (bottom 10%; n = 188) identified within the group. Design and Methods: All children completed a reading assessment and reading motivation questionnaire in their classroom; good and poor readers were selected based on their scores in the standardised reading test. Results: In the full sample, children's intrinsic reading motivation and reading efficacy correlated with their reading skill whereas their extrinsic reading motivation did not. After co-varying for differences in group composition, good and poor readers differed significantly in levels of intrinsic reading motivation and reading efficacy but not extrinsic reading motivation. Among the good readers, only extrinsic reading motivation correlated significantly with reading skill, whilst among the poor readers, no aspects of motivation correlated significantly with reading skill. Overall, poor readers' intrinsic and extrinsic reading motivations were more closely correlated. Conclusions: The relationship between reading motivation and reading skill may not be as straightforward as is commonly thought; extrinsic motivation and not intrinsic motivation was associated with variation in reading skill among children with excellent reading scores. (Contains 4 tables.)