ABSTRACT Studies show that technology can have a positive influence on student achievement and motivation; however, the use of technology for educational purposes is rather modest. Research has shown teachers’ attitudes to be a key aspect of technology use. However, there is no agreement on which attitudes we should focus on. The aim of the present study was to determine which attitudes may be differentiated empirically in a sample of STEM teachers in the context of mobile devices in teaching and to what extent these factors help to predict willingness to use mobile devices. The study was conducted among 377 STEM-subject teachers. The results showed that performance expectancy, effort expectancy and technology attitude are highly correlated for teachers. It would appear that social aspects (social influence and facilitating conditions) may serve as facilitators for teachers’ attitudes in the model, predicting 52.5% of teachers’ behavioural intention to use mobile devices for teaching.