BACKGROUND Fine needle aspiration cytology (FNAC) combined with rapid on-site evaluation (ROSE) and ancillary techniques is an accurate diagnostic tool for many pathologies. However, in some cases, it may not be sufficient for actionable diagnoses or molecular testing, especially for cases that require large immunohistochemical panels or cases in which histological features are mandatory for the diagnosis. Core needle biopsy (CNB), on the contrary, provides samples that are suitable for histological features and sufficient for all ancillary studies. However, CNB is often performed by radiologists or clinicians without the direct participation of cytopathologists, which can lead to missed or delayed diagnoses. This study reports on the experience of combining FNAC and CNB performed in one setting by cytopathologists. The aim was to evaluate the impact of CNB on FNAC and the diagnostic efficiency of the combined procedures. METHODS One hundred forty-two FNAC and CNB procedures performed in the same setting over a period of 2 years were analysed. The FNAC diagnoses were compared and integrated with the subsequent CNB diagnoses. The impact of CNB was categorized as follows: non-contributory, in cases of inadequate samples; confirmed, when the CNB and FNAC diagnoses were the same; improved, when the CNB diagnosis was consistent with the FNAC diagnosis and further specified the corresponding entity; allowed, when CNB produced a diagnosis that could not be reached by FNAC; changed, when the CNB changed the previous FNAC diagnosis. RESULTS CNB confirmed the FNAC diagnosis in 40.1% of cases (n = 57/142). CNB improved the FNAC diagnosis in 47.2% of cases (n = 67/142). CNB allowed a diagnosis that could not be performed on FNAC in 2.1% of cases (n = 3/142). CNB changed a previous FNAC diagnosis in 2.1% of cases (n = 3/142). CNB was non-contributory in 8.4% of cases (n = 12/142). CNB produced a positive impact on the whole diagnostic procedure in 51.4% of total cases (n = 73/142). The combined FNAC and CNB resulted in actionable diagnoses in 91.5% of all cases (n = 130/142). A complete molecular assessment was successfully performed in 14.7% of cases (n = 21/142) utilizing either FNAC or CNB material. CONCLUSIONS The combined use of FNAC and CNB in one setting improves the diagnostic accuracy of both procedures. This approach exploits the advantages of each procedure, enhancing the accuracy of the final diagnosis.