A method and apparatus for determining the position of mobile terminals in a cell of a mobile communication network where timing-based alignment is employed for terminal transmissions in timeslots to a serving base station. First, the distance to the base station is determined for at least one mobile terminal in the cell. A current timing value used by the at least one mobile terminal for timing adjustment of signal transmissions is also obtained. A relation between the determined timing independent distance and the obtained current timing value for each terminal is then estimated, and a timing bias of the cell or the at least one mobile terminal is determined based on the estimated relation. The position of subsequent terminals can then be determined using a timing based positioning method and the timing bias, such that the current timing value used by the subsequent terminal is adjusted by the timing bias.