The first stage of the Siberian Knot's autumn migration between its breeding grounds in Taimyr, Siberia and the W European tidal flats is still poorly understood, despite our expanding knowledge of this species. This paper analyses data (1988–1995) on the numbers of Knots and the timing of their migration in the Puck Bay region of the Baltic Sea (N Poland). The timing varied greatly between seasons. The timing of adult migration is linked to breeding success. In seasons with low breeding success both males and females leave the breeding grounds earlier, and the correlation between the mean date of adult migration and the number of juveniles is consistent with this phenology. The differences between the departure dates from the Taimyr breeding grounds provided by published sources and the dates of arrival at Puck Bay suggest that Knots cross the northern tundra regions very quickly (at least, the earliest birds to arrive do so). The numbers of juvenile Knots turning up on the Polish coast appear to depend not only on the lemming cycle in the breeding grounds, but also on other factors, like local weather conditions, which could influence the number of juveniles observed.