The relative importance of traditional techniques used in the diagnosis of haematological neoplasms has altered during the past decade. Cytology and histology retain their central role but the importance of cytochemistry has declined, except in the diagnosis of AML. Immunophenotyping is of major importance in the diagnosis of ALL, some categories of AML and the LPDs. Cytogenetic and molecular genetic analysis are important in the diagnosis of CML and are becoming increasingly important in the diagnosis of chronic LPDs and other haematological neoplasms. Diagnostic haematology laboratories which are not specialist leukaemia centres should have ready access to all of these techniques to ensure optimal patient management. However, not all techniques need to be performed in every laboratory.