Objective: To evaluate the diagnostic validity of fine-needle capillary cytology (FNCC) in palpable tumours. Material and methods: A retrospective, single-tray, cross-sectional diagnostic test study was carried out. We reviewed the cytological reports of the case files of the Cytology Unit of the Northern Regional Institute of Neoplastic Diseases (IREN) from January 2012 to December 2016. Results: A total of 332 patients were selected, with an average age of 54.77 years (range 13-90 years); 61.4% of patients were female. The most frequent anatomical sites were lymph nodes (49.7%), thyroid (13.3%), breast (12.3%) and soft tissues (11.4%). Twenty-five cytologies did not have a histological correlation and six showed an atypical result. In the lymph node study, the most frequent pathology was metastatic carcinoma (49.7%), followed by lymphoma (13.3%). The FNCC had a sensitivity of 99.55%, a specificity of 98.77%, a positive predictive value of 99.55% and a negative predictive value of 98.77%. The positive likelihood ratio was 80.63%. Conclusions: FNCC is a useful, safe, reliable and economical ambulatory technique with minimal complications and high diagnostic accuracy.