Deveci Koçbilek, Z.Karayurt, U.Bilik, O.Eyigör, S.2026-02-252026-02-2520261538-2931https://doi.org/10.1097/CIN.0000000000001336https://hdl.handle.net/20.500.14365/8724This single-blind, randomized controlled design study aims to examine the effect of a mobile-based Lymphedema Self-care Support Program on self-care, the quality of life, and lymphedema symptoms in women with breast cancer–related lymphedema. A control group was offered online standard lymphedema education, and an intervention group was provided with the mobile-based Lymphedema Self-care Support Program in addition to the standard education. Outcome measures were self-care, quality of life, lymphedema symptoms, and arm circumference measurements. The intervention and control groups were similar in sociodemographic and clinical features at baseline. Although there was a significant difference in the mean self-care scores between the groups, there was no significant difference in the mean scores on the quality of life and lymphedema symptoms. The mean scores on self-care and the quality of life increased and arm circumferences decreased significantly across time in the intervention group. The mobile-based Lymphedema Self-care Support Program is a beneficial method to enhance self-care and the quality of life and reduce symptoms in women with breast cancer–related lymphedema. Breast cancer survivors can increase their self-care practices, prevent an increase in their symptoms and arm circumferences, and improve the quality of their lives by using the mobile-based Lymphedema Self-care Support Program. © 2026eninfo:eu-repo/semantics/closedAccessBreast CancerLymphedemaMobile ApplicationQuality of LifeSelf-CareArticle10.1097/CIN.00000000000013362-s2.0-105029794140