Beta-thalassemia major (B-TM) is an inherited hematological disease that affects nearly 300 million people worldwide. This study aimed to evaluate the effects of group-based mobile learning on stress, anxiety, depression, and pain among beta-thalassemia major patients. This randomized clinical study was conducted on 48 patients with beta-thalassemia major in Jahrom, Iran. Participants were randomly assigned to the control and intervention groups. Their partners in the intervention group were trained in self-care through mobile learning. The 21-item Depression, Anxiety, and Stress Scale and a visual analog scale for pain assessment were used to collect the data. Data were analyzed using the Statistical package for the Social Sciences version 23.0. Although there was no significant difference between the control and intervention groups in the mean pre-test scores of depression (P = .21), anxiety (P = .05), stress (P = .48), and pain (P = .46), the mean post-test scores of depression, anxiety, and stress in the intervention group were significantly lower than the control group (P = .0001). The mean scores of depression (P = .33), anxiety (P = .74), stress (P = .83), and pain (P = .6) did not change significantly in the control group, while all these mean scores decreased significantly in the intervention group for DASS (P = .001) and pain (P = .002). Group-based mobile learning is effective in reducing depression, anxiety, stress, and pain in B-TM.