Background/Objectives: Obesity is a growing public health challenge due to its high prevalence and associated comorbidities. Bariatric surgery is the most effective treatment for achieving sustained weight reduction when more conservative treatments have failed. This study evaluates the impact of a nurse-led telecare follow-up programme in the immediate postoperative period for patients who have undergone bariatric surgery. Methods: A quasi-experimental study was carried out in two hospitals in southern Spain. We included 161 patients who met the inclusion criteria: a body mass index (BMI) ≥ 40 kg/m2 or a BMI ≥ 35 kg/m2 with associated comorbidities, and the failure of non-surgical treatments. Patients were divided into two groups: the intervention group (IG), which received follow-up telephone calls from a specialised nurse during the first 30 days post-surgery, and the control group (CG), which received standard care. The nurse, who was available 24 h a day, answered questions and dealt with queries over the phone or referred patients to the emergency department if necessary. Several variables were recorded, including the number of telephone consultations, reasons for consultation, number of emergency visits, readmissions, and surgical reinterventions. Results and Conclusions: The IG showed a significant reduction in ED visits (4.9% vs. 30% in CG), and consultations were mainly related to diet and drainage. The nurse telecare intervention significantly improved postoperative recovery by reducing complications and optimising the safety and quality of postoperative care. These results reinforce the importance of personalised follow-up in improving clinical outcomes in bariatric patients.