The variability of water outflow and fluvial transport in the Upper Wieprz River catchment (300.3 km2) in Central Roztocze is presented based on results of daily measurements in Guciów from the period 1996– –2016. The study period was characterised by high variability of annual precipitation totals – from 563.2 mm (2003) to 932.9 mm (2010), with the mean annual value of 735 mm. Mean annual discharge in the Wieprz River ranged from 0.91 m3·s–1 (1996) to 2.27 m3·s–1 (2010), and extreme discharge values varied from 0.5 m3·s–1 (1996) to 13.1 m3·s–1 (2005). The variability of annual, monthly, and extreme discharges was moderate. The specific runoff index amounted to 4.5 dm3·s–1·km–2, and varied from 3.0 dm3·s–1·km–2 to 7.6 dm3·s–1 ·km–2. The mean annual outflow of the Wieprz River in Guciów amounted to 142 mm, and varied from 95 to 239 mm in particular years. The outflow regime showed features of nival type, moderately developed. The dynamics of transport of solutions and suspensions corresponded with seasonal and annual changes in outflow from the Wieprz River. Mean annual fluvial transport varied from 7.8·103 t (1996 and 2004) to 18,0·103 t (2010), whereas transport of solutions constituted 89–97% of the total flux. The mechanical and chemical denudation indices calculated for the catchment amounted to 2.4 and 36.1 t · km–2 per year, respectively. In spite of the evident increasing trend in annual atmospheric precipitation totals, water outflow did not increase, contrary to forecasts, and fluvial transport, particularly that of suspensions, showed a tendency of a slight decrease.