An analysis of current velocity, temperature and salinity data collected between 15 November 1990 and 24 July 1991 in the Ibiza Channel has been made to illustrate the circulation of the different water masses within this area. At certain stages of early winter, outstanding intrusions of Modified Atlantic Water, lasting a few days, have been observed flowing northwards along the eastern part of the Channel. Western Mediterranean Intermediate Water appeared for the first time during the middle of February; from March onwards, the thickness of the layer of this water mass increased until it reached its greatest presence during early summer. Simultaneously, the amount of Levantine intermediate Water decreased at the mooring site, being replaced by the MAW. Western Mediterranean Deep Water was detected flowing northwards by our deepest measuring device during June and July. This flow may be a seasonal feature of the circulation in the Channel, linked to the production of Deep Water.