Purpose <p>The most common cause (&gt; 80% of cases) of primary hyperparathyroidism (PHPT) is parathyroid adenoma. Its diagnosis is conventionally made by cervical ultrasound and ^99mTc-MIBI scintigraphy. However [¹⁸F-Choline PET-CT ( [¹⁸F-FCh PET-CT) offers greater sensitivity and specificity, although at a high cost, which prevents it from being a first-line diagnostic method.</p> Methods <p>Observational retrospective cohort study of 100 consecutive patients operated on for PHPT by parathyroidectomy in a tertiary hospital. Patients were divided into two groups: Group 1, patients with successful diagnosis using conventional tests (42 patients) and Group 2, patients with an initial failed diagnosis who required ¹⁸F-FCh PET-CT (52 patients). A group with an ideal diagnostic strategy using only ¹⁸F-FCh PET-CT was simulated and the costs were compared with the groups in the sample.</p> Results <p>The sample finally analyzed 94 patients, 78.7% female, mean age 61.73 years. 55,3 % of the patients required a ¹⁸F-FCh PET-CT for the location diagnosis. The group 2 required more consultations, more complementary tests and a longer interval between the first consultation and the intervention. The ideal diagnostic strategy (€1,399.77/patient) represents a lower cost than the other strategy (€1,730.61/patient).</p> Conclusion <p>The diagnosis of location of a parathyroid adenoma with ¹⁸F-FCh PET-CT required fewer complementary tests and consultations, reducing the interval until surgical intervention, with no difference in surgical results. The costs if ¹⁸F-Ch PET-CT is performed as the only location diagnostic test are lower when a group of patients is studied, so its use is recommended as a first line diagnostic tool.</p> <p><b>Clinical trial number</b>: Not applicable.</p>