This paper extends the range of diameters (0.009-0.127 m) for which information on the maldistribution of the phases at a T-junction is available. Data are presented for a smaller T-junction whose diameter is 0.005 m in all branches. The flow rates studied result in annular flow approaching the junction. Cas superficial velocities of 46-60 mis and liquid superficial velocities of 15-20 m/s were studied. When the present data are compared to those from larger diameter junctions for similar superficial inlet velocities, it is seen that decreasing the pipe diameter increases the fraction of liquid taken off. It is suggested that this trend is due to the lower entrained fraction and more uniform film around of the pipe circumference for the smaller pipes. The measured split data were compared with the predictions of published models. (C) 2000 Elsevier Science Ltd. All rights reserved.