BACKGROUND Teenage pregnancy is emerging as a global public and health problems especially in developing country like ours. Maternal age has an important impact on pregnancy outcome especially when it comes to extremes of age. It is an important risk factor for making a pregnancy high risk. The purpose of this study is to compare the foetal and maternal outcome in adolescent pregnancy with mothers of normal reproductive age group (20-34). The objectives of the study were-1) To calculate the incidence of adolescent pregnancy in a tertiary care centre, RIMS, Ranchi where this study has been done and 2) To note the influence of age on foetomaternal outcome. MATERIALS AND METHODS This is an observational comparative case study conducted in period of October 2016-September 2017 in the department of Obs. & Gynae, RIMS, Ranchi. This study includes apparently healthy mothers aged <19 yrs. (study group) and mothers aged 20-34 yrs. (control group), irrespective of parity attending in our department and excludes mothers of age >35 yrs. Detailed medical history of both groups was taken. Mothers and babies were assessed for various factors before, during and after delivery. Statistical analysis was done using chi square test. RESULTS In the one-year period of observation, it was noted that significantly high no. of control groups was found to be literates and working. Antenatal complications like anaemia, preeclampsia, APH etc., were predominant in teenagers. Significantly high no of LBWs is seen in study group. Other perinatal complications like neonatal jaundice, respiratory distress syndrome, FTT etc., and puerperal complications are more common in study group. CONCLUSION This case study picture clearly shows that age of the pregnant mother is an important risk factor. Adolescent mothers carry higher risk of antenatal and puerperal complications, moreover babies born to teenage mothers suffer from perinatal complications.