Objectives: Lifelong self-care is recommended for lymphoedema (LE) prevention. However, the process of developing self-care practices among cancer survivors remains unclear. This study aimed to describe the development of self-care over time, comparing survivors with and without prior self-care practices for LE. Sample and setting: Between September 2023 and June 2024, 14 breast (n=10) and gynaecologic (n=4) cancer survivors without LE participated in a 9-month online LE prevention programme in Japan. Sessions covered self-care, healthy lifestyle, stress reduction, and follow-up. Participants’ ages ranged from 31 to 62 years, and duration since cancer diagnosis ranged from 1 to 22 years. Procedures: Following institutional ethical approval, the participants were recruited through a hospital and a market research company. After providing informed consented, they completed a baseline survey and participated in the programme. Participants set their self-care goals and recorded their self-care behaviours, challenges, causes of anxiety and stress, coping strategies, and outcomes using monthly worksheets. They were classified into precontemplation (n=8) and action (n=6) groups. Content analysis was performed on the longitudinal qualitative data by group, and the findings were compared between groups. Results: Although the extracted categories were similar, self-care development differed between the groups. The action group reported difficulties with lifestyle modification, managing symptoms in the affected limbs, and continued self-care using external resources. This group used cognitive and behavioural approaches to manage their anxiety and stress and generally maintained a self-care habit characterised by ease and enjoyment. The precontemplation group had more practical questions about self-care and tended to postpone actual self-care. Some required more strategies to manage stressful personal lives and faced challenges in sustaining a self-care habit. Conclusion and clinical practice: Self-management developed differently depending on previous self-care practices for LE. Greater practical and psychological support should be tailored for survivors lacking prior experience of self-care.