Abstract Aim This project investigates whether patients received appropriate post-operative biochemical monitoring and micronutrient replacement after bariatric surgery, as per British Obesity & Metabolic Surgery Society (BOMSS) guidelines. Method A total of 27 Patients underwent either gastric bypass or sleeve gastrectomy between 1st August 2020 to 31st July 2021 at Northumbria Healthcare NHS Foundation Trust. Data was collected retrospectively. Results Most patients received appropriate micronutrient replacement, with 82% for A-Z multivitamin, 84% for calcium supplement, 72% for vitamin D supplement, 96% for vitamin B12 supplement, and 91% for ferrous sulphate for menstruating women. Similar results found with post-operative blood tests at 6 months, 81% for FBC/LFT/U&E, 74% for ferritin and folate, 74% for calcium and vitamin D, and 70% for vitamin B12. Similar findings at 12 months, 74% for FBC/LFT/U&E, 74% for ferritin and folate, 78% for calcium and vitamin D, 70% for vitamin B12, 67% for zinc, 70% for copper, and 67% for selenium. However, compliance with blood tests at 3 months was inferior, 48% for FBC/LFT/U&E, 37% for ferritin and folate, 37% for calcium and vitamin D, and 44% for vitamin B12. Conclusions Most patients received appropriate biochemical monitoring and micronutrient supplements. Unfortunately, less than half of the patients received monitoring blood tests at 3 months, which is a time where post-operative complications such as malnutrition can be identified and corrected. Several factors may have contributed to this, such as delay in communication between secondary and primary care or lack of facilitation to phlebotomy services.