The relationships between visuo-spatial abilities and geometry performances in school-aged children were examined. A battery of tests assessing non-verbal reasoning, visuo-spatial mental imagery, and academic achievement in geometry (i.e., geometric knowledge and geometric problem-solving competencies) was presented to 162 8-9.5-year-old pupils attending primary school. After controlling for age, significant associations were found between non-verbal reasoning abilities and knowledge in geometry (r = 0.31, p = 0.013) and geometric problem-solving skills (r = 0.35, p = 0.005), respectively. Similarly, using age as covariate, mental imagery abilities were significantly related to geometric knowledge (r = -0.28, p < 0.001) and geometric problem-solving skills (r = -0.24, p = 0.002), respectively. Furthermore, pupils with high visuo-spatial mental imagery abilities outperformed their peers with low visuo-spatial competences in the geometry tasks and further visuo-spatial abilities measure computed by their teachers. Finally, male participants showed better geometry skills than females.