A heatable high pressure cell for angle dispersive neutron powder diffraction has been developed. This cell, called Kiel-Berlin Cell I, is of the piston–cylinder-type and based on a design first introduced by McWhan. High temperature conditions under high pressure are achieved by a graphite resistance heater surrounding the sample container. The cell operates up to temperatures of 700 K and pressures of 1.5 GPa, simultaneously. We report the design of the cell along with calibration data. We also give a brief and representative account of pressure-temperature-dependent studies in which the present cell was used. ©1997 American Institute of Physics.