Short electric band heaters (L/D-i < 1.5) are constructed for the ease of implementation in small scale heating applications. They are usually mounted side-by-side in series along the external wall of a pipe for heating the fluid within the pipe. There are no rules-of-thumb available about designing such a system to achieve good uniformity of the temperature profile at the pipe inner surface beforehand. Non-uniformity can cause preferential fouling at hotter spots. This study focuses on the axial uniformity of heating along a pipe inside which the heated fluid if flowing. The situation has been simplified a great deal in mathematical terms from the corresponding conventional conjugate problem considered previously due to the small temperature rise in the fluid flow through one section of the pipe which is heated by one band heater. Similarity parameter sets have been deduced and verified by numerical simulations. The worst scenario of non-uniformity for such short band heaters, that is when L/D-i = 1.5, is presented in this paper. This may be used for designing a system to minimize the non-uniformity in terms of choosing the right pipe material, percentage of heater wire coverage in the band heater, etc. Copyright (C) 2002 John Wiley & Sons, Ltd.