Background: Excess weight is associated with an increased risk of lymphoedema in patients with breast cancer. Studies are lacking about the experiences of patients with comorbid lymphoedema and obesity. Aims: This study aimed to examine lymphoedema knowledge, management barriers and impact on wellbeing in those with lymphoedema and obesity. Methods: Twenty-six patients (10 male and 16 female) with a mean body mass index of 35.89 and secondary lymphoedema participated in focus groups. Using a grounded theory approach, transcript data were coded individually and compared. Results: Four themes were identified: (1) excess weight exacerbates lymphoedema and there were struggles to lose weight even though it would help manage symptoms; (2) patients were upset that physicians lacked lymphoedema knowledge and/or oncologists did not communicate with them about the risk of lymphoedema; (3) physical therapists were the main source of information; and (4) patients used multiple coping strategies to address challenges. Conclusion: Physicians need more training about lymphoedema and should be willing to refer patients for lymphoedema and weight loss treatment. Oncologists should communicate with patients about the risk of lymphoedema before cancer treatment.