The present research investigated the possibility to foster positive classroom climate, achievement emotions, and adaptive beliefs about errors by manipulating teachers' error handling strategies. Through a pre-post experimental design, teachers' error handling strategies were manipulated during a fictitious lesson in the primary school context. The experimenter, who was presented as an external teacher, carried out the lesson using positive and supportive error handling strategies (experimental condition) or neutral error handling strategies (control condition). The aim was to test differences in pupils' perceived error climate, achievement-related emotions, and error beliefs comparing the two conditions. A total of 108 fifth-grade primary school pupils took part in the research. The main results revealed that dealing with pupils' errors using a constructive and encouraging strategy that supports them in learning from their errors (positive error handling) increased, compared with a neutral error handling, their perception of being in a trustful and supportive learning climate. This study represents the first experimental attempt in which error-related teaching strategies have been directly manipulated to identify their causal impact on primary school pupils' perceived error climate.