In the year 2020, COVID-19 spread globally. The increase in cases and deaths has created problems such as stress, anxiety, and depression in health workers. The health care workers (inclusive of students in professional practices are vulnerable to psychiatric pathology due to their exposure to the virus, their increased risk of contagion and even death, overload of functions, pressure for decision-making, the close experience of patients, relatives, and colleagues’ pain, and the requirement to function at the top of capacity. The objective of this research is to analyse the personal and academic factors of stress development in nursing students, during clinical practices in the COVID-19 context. It is a cases and controls study, with 154 students who attended clinical practices during the period of May-August 2020. High levels of stress were found in 61% of students, 34 of these had difficulties concentrating (OR: 3.08), 64 participants reported fear of contact with COVID-19 patients, (OR: 1.9) and 68 participants were identified with inadequate knowledge of COVID-19 transmission (OR: 1.5). The study found that the transition to virtual classes as a strategy to reduce contagion increases three times the possibilities of developing stress, another variable that doubles the risk of stress is the fear of caring for a patient with COVID-19 who has not been diagnosed.