Almost after a century, the occurrence of Zingel streber (Siebold, 1863) was recorded again in the area of confluence of the rivers Morava and Dyje. The population consisted of fish 0+ to 5+, with 0+ group predominating in the sample, indicating that the species had successfully reproduced in 2003. Analysis was made of their karyotype (n=5) and meristic characters (n=10). The following was the result of a study of growth of standard lengths (n=16): SL1 – 81 mm, SL2 – 114 mm, SL3 – 130 mm, SL4 – 146 mm, SL5 – 166 mm. The biggest individual was a female 5+ of age, TL 200 mm, SL 180 mm. The habitat types preferred by individuals 0+ were the rapidly flowing sections with gravel bottom, in which the stream velocity was 0.2–0.6 m.s-1. Re-occurrence of this species was facilitated by the marked improvement of water quality after 1990 as well as by the barrier-free connection of sections of the rivers Morava and Dyje with the Danube via the Slovakian-Austrian part of the River Morava. Further dispersal of this species is limited by the weir in r.km 26.7 on the Dyje, and six weirs between r.km 74.1 and r.km 101.8 on the Morava. Z. streber is protected by national law and the area mentioned above has been proposed as a pSCI for the NATURA 2000 system.