Delayed puberty is defined arbitrarily on the basis of statistical consideration, when no signs of puberty have occurred at 2.0 SD (13.4 years in girls and 13.8 in boys) above the mean chronological age for the onset of puberty. The vast majority of these patients have no endocrine abnormality and their pubertal development and growth spurt are simply consequences of primary delay (constitutional delay of growth and puberty (CDGP)) or secondary delay due to a chronic disease of childhood, such as asthma. However, a small proportion may have pathological causes of delayed puberty which must be careful identified as specific management may be required. Associated with delayed puberty, the growth spurt is always delayed which is why the condition is described as delayed growth and puberty. Short stature and lack of sexual development may lead to emotional and social difficulties and in some patients their consequences can persist when 'normal' height and full sexual maturation are attained. Recent data also suggest that a delay in the 'tempo' of pubertal maturation may interfere with the normal bone accretion occurring during puberty, later causing osteoporosis. Such findings suggest that a new approach in delayed puberty may be necessary not only for psychological reasons but also for optimizing bone mass accretion.