Complementary and Alternative Medicines (CAM) are being questioned and analysed in Spain given the absence of hard scientific evidence to support them (MSPSI, 2011). Despite this, the number of users of CAM is increasing (Munoz & Lopera, 2014). The development of scientific competences and the capacity to understand scientific knowledge and judge the reliability of information are two objectives of the Degrees in Pre-school and Primary School Education. Natural Science Teaching has demonstrated that socio-scientific issues offer an interesting debate to learn concepts and develop critical thinking (Kolsto, 2001; Torres & Solves, 2012; Zeidler, Sadler, Applebaum & Callahan, 2009). In order to approach CAM as a socio-scientific issue in a future teaching proposal, we have studied the perceptions, attitudes and arguments of teacher training students in relation to these medicines and their use. We designed a research in two stages. First, a questionnaire including three open questions (meaning of CAM, motivation to use them and the differences with conventional medicine) was carried out. 209 students with an average age of 27 years and mainly females (85%) answered the questions. The second part of the research was done with four focus groups; we posed questions to the groups based on the CAM Health Belief Questionnaire (CHBQ) (Lie & Boker, 2004). The results show that students are favourable to CAM because these therapies deal with the emotional needs of the patient and their remedies are "natural". Students think that conventional doctors don't pay attention to emotions. Students consider CAM as a remedy of illnesses as anxiety, depression and muscular problems caused by stress due to actual lifestyle. Other misconceptions we found are related to the role of scientific medicine in society and the word "chemical" as being synonymous to conventional drugs that cause undesirable secondary effects. We suggest the inclusion of CAM in future teaching proposals as a socio-scientific issue to improve students' scientific literacy.