In this study, we examined relations between kindergartner's emotional security, task involvement and achievement and teacher's supportive presence in a cognitive training setting, in which the familiarity of the teacher was varied. Participants were 48 kindergarten children (mean age = 51.65 months); 16 children were trained by their regular teacher (experimental group 1), 16 by a less familiar teacher (experimental group 2) and 16 received no training (control group). In three training sessions, children worked in pairs on a new categorization and recall task. Trained observers rated children's emotional insecurity and task involvement and teacher's supportive presence. Furthermore, spontaneous recall during the training was assessed. In addition, categorization and spontaneous recall was measured in various test sessions. Children's emotional insecurity during training negatively affected involvement. Involvement on its turn positively influenced spontaneous recall during training. In addition, emotional insecurity had a direct negative effect on spontaneous recall in a test situation. No effect of familiarity or supportive presence of the teacher on emotional security was found. Training conditions did not affect test performances. Findings suggest that children's involvement is important for learning and that experiences of emotional insecurity may negatively affect task involvement, test performance and eventually school achievement. Teachers in general seem capable of providing children with some sense of security. (Contains 1 figure and 9 tables.)