To promote a change in epistemic beliefs in in-service university teachers and a consequent improvement of their teaching methods to encourage students to take a more sophisticated approach to learning their subjects, I explored the relationships between epistemic beliefs and approaches to teaching in a group of 111 lecturers across different disciplines at the University, Colombia, South America. This correlational research is based on epistemic metacognition research (Hofer & Pintrich, 1997) and phenomenography research (Marton & Booth, 1997). The methodology comprised quantitative and qualitative research techniques including the participation of a selected sample in face-to-face and online interventions. I also conducted two questionnaires, the Discipline-Focused Epistemic Beliefs Questionnaire (DEBQ) (Hofer, 2000) and the Approaches to Teaching Inventory (ATI) (Trigwell & Prosser, 2004). Furthermore, I carried out interviews that were later analysed according to phenomenographic principles. Based on the findings, I concluded that the DEBQ and the ATI are suitable in measuring epistemic belief and approaches to teaching in a university setting. As I found correlations between epistemic beliefs and approaches to teaching, I concluded that epistemic beliefs do play an important role and influence the way in which teachers approach their own teaching. Additionally, as there was a statistically significant decrease in the Information Transmission/Teacher-Focused Approach through the online intervention, and as epistemic beliefs and approaches to teaching are correlated, the results indicate the possibility of a change from naive to more sophisticated epistemic beliefs. The results also indicate the possibility of changing epistemic beliefs and approaches to teaching through an online intervention or facilitated by online learning environments. The results also indicate the possibility of changing approaches to teaching through short-term interventions as well. Regarding disciplinary differences, lecturers did have different perceptions. I concluded that discipline did have an influence and an impact on epistemic beliefs and approaches to teaching. There was no statistically significant difference between genders or the number of years of experience. Finally, there were variations in lecturers‘ ways of experience learning, teaching, Information and Communication Technologies (ICTs), and knowledge. The description of lecturers' experiences of learning, teaching, ICTs, and knowledge shows 13 qualitatively distinct categories of descriptions. Also 13 holistic views, in a form of outcome space, were derived from their various ways of experiencing those phenomena.