Detailed paleomagnetic records of both the directional and relative field intensity changes occurring during three sequential polarity reversals have been obtained from marine clays of Serravallian-Tortonian boundary age in the island of Zackinthos (Greece). The three reversals are characterized by a complicated geometrical and temporal structure. Periods of rapid changes of the geomagnetic field vector alternate with periods of near stationarity. Different episodes of collapse and recovery of the field intensity and the presence of “rebounds” have been documented. Overall the records obtained here are reminiscent of volcanic records and appear much more complex and quite different from those previously obtained from upper Tortonian marine clays in Crete, in the same geographical area. The bearing of these results on some of the published reversal models is discussed, and it is also suggested that the greater complexity of the Zackinthos records might be related to the fact that they are exactly coeval with the last reversal spurt documented by reversal frequency analyses.