We report our experience of non-tuberculous mycobacterial infection associated with the tunnel of Hickman-Broviac central venous catheters in immunosuppressed patients with haematological malignancies undergoing high-dose chemotherapy supported by BMT. The problem is rare and difficult to treat. Our cases are unique in developing tunnel site mycobacterial infection well after the tunnelled catheters were removed. We diagnosed one case of Mycobacterium chelonae, which is a well-documented cause of such infections, and two cases of Mycobacterium haemophilum, which are the first reported cases in this setting. Early wide surgical excision of the infected tunnel site and prolonged antibiotic therapy is necessary. Despite these measures recurrence occurred in two cases. Close liaison with the microbiology laboratory is needed to ensure the appropriate culture media and conditions are used for these fastidious organisms. Empiric antibiotic regimens should be based on the likely organism. Drugs active against M. chelonae and M. haemophilum should be included.