Many studies propose that chess is a game requiring cognitive skills and has positive effects on mental development. In recent years, chess training has also been emphasised as important during the early childhood period. However, no studies have been done with six-year-old children. The purpose of this study was to investigate whether or not chess training for six-year-old children would affect the development of spatial concepts such as forward-backward, between-next to, in front-behind, diagonal, far-near, corner, pattern and symmetry and whether or not there are differences according to child gender. Subjects were 50 children who had previously taken chess courses and 50 children who had not taken chess courses. A group of 100 six-year-old children was given a concept test. A test containing the concepts used in chess instruction and a chess board to be used in applying the test were developed by the researcher. After the obtained data were analysed, K-R 20 = 0.92 was found for the concept test. The Mann-Whitney "U" test, based on the children's scores "t" from the concept test, revealed a statistically meaningful difference in all concepts in favour of the children who took chess courses, but showed no meaningful gender differences for any of the concepts. (Contains 3 tables.)