It is controversial whether obesity in children is associated with earlier onset of puberty and advanced appearance of distinct parameters of pubertal development. To investigate the impact of obesity on markers of the onset and parameters representing stages of puberty, we analyzed auxological parameters and secondary sex characteristics in three representative cohorts of Caucasian children. Body weight, height, peak height velocity and pubertal stages were evaluated in two recent German cohorts (CrescNet and Leipzig Schoolchildren), and a historical Swiss cohort. According to body mass index (BMI), children were classified into three weight groups of lean, overweight, or normal weight with limits defined below -1.28 and above +1.28 BMI SDS. Peak height velocity (PHV) occurred significantly later in lean compared to normal weight children in the CrescNet and Swiss cohort, while there was no difference between obese and normal weight children. There was a trend towards acceleration of parameters of puberty onset and progression in obese children in all three cohorts. Height SDS was significantly higher in obese children compared to normal weight peers, but after completion of pubertal development it was similar in adolescents. The impact of overweight on the acceleration of puberty seems to be slightly stronger in boys. Once girls have reached a critical weight for entering the process of maturation, further increase in body weight does not seem to advance the onset of puberty.