The aim of this study is to determine the positive/negative teacher behaviours which teacher candidates observed during their primary and secondary school years and the effects of these behaviours on themselves. The research was conducted in the spring term of 2012-2013 academic year with 88 teacher candidates (52 females and 36 males), studying in Gazi University. In the study, qualitative research method was used. When obtained findings were analysed, positive teacher behaviours, which teacher candidates remembered, fell into the categories of providing with motivation and self-confidence, tolerance, patience, listening and caring, reinforcing, egalitarian attitudes, positive warning, encouraging, mediation and problem solving. So as to negative teacher behaviours, they fell into the categories of physical punishment, insulting and humiliating, scolding, blaming, discriminatory and indifferent attitudes, negative warning and authoritative attitudes. In addition, in the study, it was found out that teacher candidates were influenced by positive/negative teacher behaviours, which they observed, in different ways.