The main focus of this paper is on a description of diagnostic methods used in lymphoma diagnosis. Here a brief description of each method such as routine histopathology based on paraffin-embedded tissue samples with optional immunohistochemical studies was presented. Characteristics of flow cytometry, electron microscopy, as well as cytogenetic studies and statistical analysis were introduced. For each method diagnostic contributions as well as limitations were described. The second part of the paper presents a brief description of the majority of lymphomas based on the new version of WHO classification. Additionally, indications of which features of immunophenotype and cytogenetic abnormalities should be taken into account during diagnosis and patients’ prognosis were suggested.