For students who perform inconsistently across subjects, teachers face challenges in formulating track recommendations, as their achievement will not point to one secondary school track. This issue may be more prominent for students from diverse backgrounds, given the achievement differences between specific subject domains within these groups. Therefore, we examined the impact of achievement inconsistency (by comparing standardised achievement levels between reading comprehension and mathematics within students) on students' track recommendations in the Dutch educational system (N = 4,248). Most student perform rather consistently. Approximately 20% of the students performed inconsistently (>1 SD difference between subjects). While the overall effect of inconsistency on track recommendations was small, achievement inconsistency primarily seemed to affect track recommendations when the inconsistency was moderate to large. Teachers formulated more "careful" (i.e., lower) track recommendations when the inconsistency was large. This effect was slightly more pronounced for higher-SES students, with no gender differences.