There are very few studies on laparoscopic adjustable gastric banding (LAGB) in obese adolescents with follow up for more than 36 months, let alone good prospective data beyond 24 months in Australian adolescents. We aimed to evaluate medium term (>36 months) safety and efficacy of LAGB in adolescents with severe obesity. This is a prospective cohort study (March 2009–December 2015) in one tertiary referral hospital including obese adolescents (14–18 years) with a body mass index (BMI) >40 (or ≥35 with comorbidities) who consented to have LAGB. Exclusion criteria were syndromal causes of obesity, depression and oesophageal motility disorders. Main outcome measures include change in weight and BMI at 6, 12, 24, 36 and 48 months post LAGB; postoperative complications; and admissions. Twenty-one adolescents (median [interquartile range (IQR)] 17.4 [16.5–17.7] years, 9 males, mean ± SD BMI 47.3 ± 8.4 kg/m2) had a median follow up of 45.5 [32–50] months post LAGB. Follow up data were available for 16 adolescents. Weight and BMI improved significantly at all follow up times (all p