Tritium concentrations in environmental waters (Vistula river water, precipitation) have been determined systematically using electrolytic enrichment and LS counting. Results for 1984-91 (yearly means) indicate that tritium concentrations continue to decline slowly and attain values of about 2 Bq/dm³ in 1991. There is no essential difference between tritium levels in surface water and precipitation; the latter tend to be lower.