Background/Aim: The environmental obesogen hypothesis proposes that exposure to endocrine disruptors during developmental “window” contributes to adipogenesis and the development of obesity. Implication of environmental endocrine disruptor such as 4Nonylphenol (4-NP) on adipose tissue development has been poorly investigated. Methods:3T3-L1 preadipocytes were incubated with different doses of 4-NP. Six-week-old C57BL/6J male mice received an intraperitoneal injection of vehicle, troglitazone or 4-NP (0.5 mg/kg). Gene expression of adipogenic regulators was analyzed. Pregnant mice were dosed by gavage with vehicle or 4-NP (0.05, 0.25 or 0.5 mg/kg) from day 12 of gestation until day 7 of lactation. The body weight, liver weight, fat mass, and serum lipids and glucose levels were measured in offspring at postnatal day 60. Results: Low concentration of 4-NP induced adipocyte differentiation, glycerol-3-phosphate dehydrogenase activity, and expression of peroxisome proliferator-acivated receptor γ as well as its target genes required for adipogenesis. 4-NP perturbed key regulators of adipogenesis and lipogenic pathway in vivo. Perinatal exposure to 4-NP increased body weight, fat mass, and serum total cholesterol and glucose levels in offspring. Conclusions:4-NP may be expected to increase the incidence of obesity and can act as a potential chemical stressor for obesity and obesity-related disorders.