The main purpose of this study was to consider the impact of Vitex agnus-castus hydroalcoholic extract, containing phytoestrogenic compounds on growth indices, sex ratio and histology of gonads of female Zebrafish. Fish larvae (4-day-old after hatching) were nourished with investigational diets (0 (control group T0), 5 g (T1), 10 g (T2) and 15 g (T3) kg−1 food) from first active feeding for 90 days. The results showed that Condition Factor (CF), Food Conversion Rate (FCR), Body Weight Gain (BWG), and Specific Growth Rate (SGR) were affected meaningfully by hydroalcoholic extract of Vitex agnus-castus (p < 0.05). These factors were significantly higher in compare to T3 treatment (p < 0.05). With increasing concentration of the extract in the diet, the ratio of female to male increased Treatment of T3 resulted in 87.23% feminization. Overall, this study suggests the use of T3 treatment achieves the best reproduction performance and a higher percentage of females in zebrafish as a model for aquaculture species. According to the results, the lowest levels of glucose and cholesterol were observed in T3 treatment and showed a significant changes with the control and treatments (p < 0.05).