Lysosomal storage disorders (LSDs) are rare inherited conditions which result from a deficiency of a lysosomal enzyme and accumulation of the related substrate. There is phenotypic heterogeneity between the different lysosomal storage disorders due to the organs affected by the different accumulated substrates which also form the basis of the classification of the disorders. The haematological presentation of LSDs varies between conditions with most notably Gaucher disease resulting in haematosplenomegaly and cytopenias due to bone marrow in involvement. LSDs may be diagnosed by the measurement of lysosomal enzymes and genetic sequencing of the relevant gene. Quantification of the accumulated in substrate in plasma or affected organs may give an indication of disease severity and subsequently respond to therapy. Treatment usually involves the replacement of the missing enzyme; however, more recently other approaches include oral substrate reduction therapy and pharmacological chaperone therapy whilst gene therapy is the subject of clinical trials.