Abstract: A rotary nozzle device (1) for development and rehabilitation of wells (3) is presented. The rotary nozzle device (1) comprises a body (5) with a longitudinal axis (7), a first group (9) of nozzles (23, 25) and a second group (11) of nozzles (27, 29). The body (5) is adapted for being inserted into a well shaft (37) and for supplying a rehabilitating or developing medium (13) to the nozzles (23, 25, 27, 29). The first group (9) of nozzles (23, 25) is arranged at a first distance (15) along the longitudinal axis (7) to the second group (11) of nozzles (27, 29). Therein, at least one nozzle (23, 25, 27, 29) is adjustable in such a way that the angle (a) between the nozzle (23, 25, 27, 29) and the longitudinal axis (7) is variable.