Objective: Previous studies have suggested the benefit of routine screening for biopsychosocial symptoms among patients with cancer. In recognition of the lack of data from low-and middle-income countries, this study sought to test and determine the effect of a mHealth program to screen biopsychological symptoms among patients with advanced breast or gynecological cancer.Methods: This was a quasi-experimental pre-post study conducted in a public hospital located in central western Brazil. Patients diagnosed with advanced breast of gynecological cancer who were about to initiate chemotherapy treatment at this institution and had access to Internet by smartphone, computer or tablet were invited to participate. Patients received training on using the app Comfort, a program developed to rate their physical and emotional symptoms during the 6-month of the proposed study. Patients were also asked to complete the EuroQOL 5D (EQ-5D-3L) every month. Mann-Whitney U test was used to determine differences among groups of patients (engaged and non-engaged). RM-ANOVA was used to determine the effect of time on mean visual analog scale (VAS) score.Results: A total of 125 patients were recruited (median age = 46.6 years old, 41.6% married). Mostly, patients possessed lower levels of education and had relatively low monthly incomes. Notably, 67.2% of patients engaged with the Comfort program, and few patients (4%) withdrew due to lack of engagement with the program or issues with internet connection. In general, patients who engaged with the program reported improvement in physical and emotional symptoms (p < 0.01), as well as in their overall quality of life (VAS; p = 0.009), compared with patients who did not engage with the program.Conclusions: This is the first mHealth program developed in Brazil for patients in a low resource setting. Our findings suggest that Comfort could be an effective resource to assist patients and health care providers track symptoms and improve patients' quality of life.