Many non-Hodgkin's lymphomas (NHLs), reactive processes and some leukemias may contain large transformed lymphocytes that resemble in appearance, and perhaps in immunohistochemical features, Hodgkin Reed Sternberg (HRS) cell or Lymphocyte Predominant cell (LP); the essential landmark for diagnosis of Hodgkin's lymphoma (HL) (Rosai, 2004). Differentiation from mimickers is important because current multimodality treatment protocols achieve cure in over 90% of HL patients with early-stage disease. In addition, some of these mimickers are non-neoplastic proliferations. Aims: This work aimed at collecting entities with HRS/LP-like cells, regardless of the likelihood of their misdiagnosis as HL, and setting broad lines that can guide final diagnosis. Methods: Data were collected from latest available editions of well-known general surgical pathology texts including Rosai and Ackerman’s Surgical Pathology (2004), Sternberg’s Diagnostic Surgical Pathology (2010), and Differential Diagnosis in Surgical Pathology (2010). The source also included specialized texts of hematopoietic disorders including Pathology & Genetics—Tumors of Hematopoietic and Lymphoid Tissues (2001), Atlas of Differential Diagnosis in Neoplastic Hematopathology (2005), and Diagnostic Lymph Node Pathology (2006). Recent published papers were employed, in addition to a website; WebPathology, from which some high quality microscopic pictures were obtained. Results: Entities with HRS/LP-like cells included mature B cell neoplasms (variants and subcategories of diffuse large B cell lymphoma, follicular lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, and composite lymphomas), mature T cell neoplasms (adult T Cell leukemia/lymphoma, peripheral T cell lymphoma, unspecified, angioimmmunoblastic lymphoma, anaplastic large cell lymphoma, lymphomatoid papulosis, and enteropathy-type T cell lymphoma), reactive lymphoproliferative disorders (infectious mononucleosis, and Kimura disease), and immunosuppression-associated lymphoproliferative disorders. Differentiation between these entities can be made through immunophentype of large cells in the cellular infiltrate combined with clinical information, morphology, and cytogenetic features when possible. Conclusion: Some of these mimickers are perfectly similar to HL. Others have superficial similarities. Apart from non-neoplastic lymphoproliferations, even weak positivity for Pax-5 in large neoplastic cells is recommended as an initial guide that excludes mature T cell neoplasm and mature B cell neoplasm of plasma cell origin in cases with HRS or LP-like cells. Further negativity or focal weak expression of a pan-B cell marker (CD20, CD79a, Oct-2, etc), suggests classical Hodgkin's lymphoma (CHL) that can be confirmed by positivity for CD15. While positivity for Pax-5 combined with strong uniform expression of a pan-B cell marker suggests nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) or other mature B cell NHL of no plasma cell origin. These broad lines are considered in context of mainly clinical information, and morphology. Features of background cells should also be considered