The present study was carried out to assess the population structure and growth with length weight relations, von Bertalanffy equations and artificial neural networks (ANNs) of topmouth gudgeon fish, between May 2015 and May 2016, in the Hirfanli Dam Lake. The age of topmouth gudgeon caught from the Hirfanli Dam Lake ranged between I to V years. The von Bertalanffy growth function growth coefficient k was 0.5 and asymptotic length L-infinity was 9.13 mm fork length (FL). The weight-length relationship is given by the regression equation W=0.01275334xL(3.0005) for all individual. Growth equations in length (mm) and weight (g g) are: L-t = 9.13 [1-e(-0.380 (t) (+ 0.5))] and W-t = 10.36 [1-e(-0.380 (t + 0.5))](3.0005) for all individual. Minimum and maximum sizes was were 2.7 and 9.2 cm FL for all individuals. Here, we examine the growth properties (length and weight) of topmouth gudgeon by modern (artificial neural networks) and traditional approaches (Length weight Relations and von Bertalanffy growth model) in the Hirfanli Dam Lake. This study presents the first LWR, von Bertalanffy and ANNs references for this species in the Hirfanli Dam Lake.