Between 1972 and 1982 34 tumour prostheses (23 total replacements, 11 semitotal replacements) of various designs were implanted at the State Orthopedic Clinic in Munich-Harlaching and at the University Orthopedic Clinic in Grosshadern. The indications were primary and secondary malignant tumours, potentially malignant tumours, peritrochanteric pseudarthroses, and loosening of prostheses where bone conditions were poor. Since 1977 only the "Harlaching" femoral tumour prosthesis, a locally developed model, has been used. Its distinguishing feature is the modular or kit principle, which renders it possible to adapt the prosthesis and define its length accurately during surgery. On the basis of 13 long-term observations, in some cases extending over 8 years, it was established that this tumour prosthesis need not be regarded as merely a palliative intervention (this applies also to younger patients with a longer life expectancy); the slight and transitory complications and the relatively good long-term functional results are encouraging.