Core needle biopsy (CNB) and fine-needle aspiration (FNA) are increasingly replacing excisional lymph node biopsy in the diagnosis of lymphomas. However, evaluation of CNB and FNA remains challenging owing to limited architectural information and the more detailed subclassification of lymphomas required by the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Our study is the largest study to assess diagnostic accuracy of CNB and FNA in conjunction with ancillary studies. We analyzed 263 cases and a diagnosis was established in 237, of which 193 were completely subclassified. In cases in which excisional biopsy was available as a reference for comparison, CNB and FNA had a sensitivity of 96.5%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 90%. CNB and FNA with ancillary studies represent a viable alternative in the diagnosis of lymphoma, as long as the number and size of cores for morphologic studies are not compromised.