Background: Suicide attempts (SA) is a global mental health problem, especially in Spain. Classical research has focused on determining the risk variables; however, few studies focused on protective variables. The aim was to assess which protective variables are more predictive of the greater or lesser lethality of a made SA. Methods: The sample consisted of 156 people who had been admitted to Emergency Department (ED) for SA, aged between 18 and 49 years Mean (M) = 26, Standard Deviation (SD) = \pm 10.8. The sample was divided into three groups defined according to the level of lethality of the made SA. Protective variables related to resilience were assessed. Results: The results suggest that self-efficacy and social support are protective predictors for future SA, along with being male. The protective variables explain the degree of lower suicide lethality, with the model proposed (set of independent variables) being significant and explaining between 0.12 and 0.68 of the dependent variable, correctly classifying 84.8% of the cases (R{}^2 de Nagelkerke = 0.76). Conclusions: This study is further evidence of the need for effective suicide prevention and intervention plans adapted to gender differences in behaviour and further research in this line of work. Future studies on large patient samples are now needed, especially with a longitudinal design.