The aim of the study was to investigate primary school teachers’ proficiency in detecting the ability-achievement discrepancy as a landmark of possible specific developmental learning disabilities (SLD). Twenty-two teachers in five schools attempted to select, in accordance with their perception and out of a larger preliminary sample, those students whose school results revealed: (a) discrepancy between school achievement and general abilities (the group of purportedly disharmonic children, GPD) or (b) concordance between general abilities and achievement (the group of purportedly harmonic children, GPH). The children were tested by REVISK, while teachers re-assessed students’ reading, writing and arithmetic performance against a simple structured questionnaire based on demands of the approved elementary school program delineated by the Ministry of Education of the Republic of Serbia. Research results indicate that more than 60% of children originally qualified to GPH have actually shown significant discrepancy between targeted scholastic skills and (normal) general intelligence. The data suggested some association between students’ disparity in attainment and teachers’ attribution accuracy, while the only homogenous quantitative marker of misplaced children were decreased values on some of the REVISK Verbal subscale tests. This study has shown that teachers can use their professional knowledge to enhance their capability to detect children with specific learning disabilities. In absence of criterion-referenced tests of reading, writing and mathematics, a structured approach to the projected course of skill progress might support teachers’ confidence regarding likely SLD.