The present study aimed at determining the relationship of anthropometric dimensions of pupils from grades 1 to 8 in primary school with the dimensions of school chairs. Two dimensions of the chairs in daily use were evaluated to ascertain whether the fit is sufficient and the effect on pupils' sitting posture. The work included a sample of 556 pupils from three primary schools in Zagreb, Croatia and two types of furniture. Dimensions of school chairs were compared with three anthropometric variables of the pupils. Descriptive statistics were analysed for all variables. These study results have shown that furniture of appropriate dimensions is not available to a large number of students in Croatia. Currently supplied classroom equipment is provided in only two sizes and does not fit the users. It is recommended that task chairs may be acceptable if they are issued in four heights or individually adjustable chairs be introduced in Croatian schools. Furthermore it is strongly recommended that schools actively promote appropriate active sitting behaviour.