The purpose of this study was to investigate some motivational factors that enhance pupils’ written homework performance as well as the obstacles that make written homework a difficult task. The method applied in this thesis is qualitative. The investigation was carried out with the help of semi-structured interviews. The results of this study indicate that the pupils have different attitudes to their written homework. The most interesting result is that not all successful pupils are highly externally motivated. The research shows that external motivational factors can enhance the pupils’ written performance well enough but they can also lead to stress and anxiety and complicate the writing process for less successful pupils. Another finding of this dissertation is that deadlines related to assessment can be treated as a negative form of external motivation.