Summary Objective: To evaluate the effect of remote intercessory prayer on clinical outcomes and mortality in critically-ill patients. Materials and methods: A randomized controlled double-blind trial was conducted. One hundred patients admitted to the intensive care unit (ICU) of Clinica de los Andes de Tunja was randomly allocated and pair-matched by severity of the illness. All patients received conventional ICU treatment according to clinical guidelines. The treatment group had intercessory prayers whereas control group did not. Baseline demographic and belief-related variables were analyzed as well as clinical outcome variables such as multiple organ dysfunction, length of stay and mortality. Results: No differences were found between groups regarding baseline variables. Length of stay was significantly increased in the treatment group (p<0.02), mortality rate was lower in prayer group (9 versus 15, p<0.05) as well as standardized mortality rate (0.67 versus 0.89, p<0.05).