Primary cutaneous B-cell lymphomas (PCBCL) represent a heterogeneous group of lymphoproliferative disorders characterized by clonal proliferation of neoplastic B-cells in the skin. The recent joint World Health Organization (WHO) and European Organization for the Research and Treatment of Cancer (EORTC) classification recognizes three major subgroups of PCBCL: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone B-cell lymphoma (PCMZL) and primary cutaneous large B-cell lymphoma, leg type (PCLBCL-LT). Recent advances in the field and the availability of new methodological tools have greatly enhanced our insights into the biology of cutaneous B-cell lymphomas and allow a more precise definition of these entities. Considerable progress over the past decade has led to significantly improved diagnostic accuracy allowing earlier diagnosis, targeted strategies and improved therapeutic results in the management of primary cutaneous B-cell lymphomas. This review presents an overview of primary cutaneous B-cell lymphomas with an emphasis on the proper incorporation of current and emerging diagnostic tools into the work-up and classification of this group of unique malignancies.