Fourteen patients suffering from various degrees of bone dysplasia and mental handicap with superimposed neuroses or psychotic episodes are reported. Known biochemical and chromosomal causes are noted. Mental states associated with syndromes and mental malfunctioning or impairment because of skeletal defects or other factors are briefly discussed. High IgE was noted in the three cases of bone dysplasias suffering from chromosomal anomalies. Importance of early diagnosis, treatment and genetic counselling in bone dysplasias to prevent mental disorder is emphasized.