The ^239,240Pu content in Baltic bottom sediments and its vertical distribution were determined. The sediment samples were collected from various regions of the Baltic Sea mainly from the southern part, in 1991-1993. Plutonium was separated by ion exchange followed by electrodeposition onto stainless steel disks. The plutonium activity was measured by a-spectrometry, with ²⁴²Pu added as an internal tracer. The vertical distribution of plutonium differs markedly depending on the sea region. In samples from the Gulf of Gdansk the highest activity concentration of ^239,240Pu (8.4 Bq/kg) was found in the 7-9 cm layer and at the Gdansk Deep in the 4-5 cm layer (4.3 Bq/kg). At the Gulf of Finland the concentration of ^239,240Pu increased continiously from the surface to 18-20 cm depth being equal 7.9 Bq/kg in the last layer. The ²³⁸Pu to ^239,240Pu ratio ranged from 0.02 to 0.05. The obtained data allow to conclude that the increase in plutonium concentration in the Baltic Sea area after Chernobyl accident is negligible. The contamination was caused mainly by nuclear weapon tests. The plutonium distribution in the Baltic Sea deposits is not uniform. In 1992 the ^230,240Pu content in the bottom sediment was about 10 times lower in the Gdansk Deep and the Gotland Deep than in the Gulf of Finland.