Lymphoma is a commonly encountered neoplasia in dogs and can present in a variety of forms. There are multiple diagnostic and treatment approaches depending on variables such as anatomic form and immunophenotype. This lecture will cover the important aspects of diagnosing and staging lymphoma patients in order to optimise treatment approach in each case, and new chemotherapy treatments will be discussed alongside tips for safely administering chemotherapy to your patients. By the end of the lecture you should be able to understand the diagnostic approach to lymphoma patients (including which information is most important to guide treatment decisions), know the different treatment options for lymphoma and how to select the optimum approach for each individual case, and understand different prognostic factors for lymphoma patients.