The present study employed a longitudinal person-centered approach to examine the profiles of reading motivation in a sample of 405 elementary school students who were tested in grades 3 and 4. Two dimensions of intrinsic reading motivation (involvement and curiosity) and two dimensions of extrinsic reading motivation (recognition and competition) were considered. Latent profile analyses revealed the same set of four profiles across third and fourth grades: high intrinsic (i.e., high on involvement and curiosity, low on recognition and competition), high involvement (i.e., high on involvement, low on the remaining dimensions), high quantity (high on all dimensions), and moderate quantity (low to moderate on all dimensions). Further results showed that 35% of the students changed their profile membership from third to fourth grade. We particularly observed an increased probability of students in the high-quantity, moderate-quantity, and high-involvement profiles to move to the high-intrinsic profile. Finally, the moderate-quantity profile proved to be significantly lower in reading amount than the other groups that did not differ significantly. Pertaining to reading comprehension, however, the two intrinsic profiles outperformed both the high- and moderate-quantity groups. The latter finding emphasizes the particular importance of intrinsic reading motivation.