Background: Trephine biopsy plays a critical role in the routine staging of lymphoma. Bone marrow involvement by lymphoma confirms advanced-stage disease and may affect both treatment and prognosis. Therefore bone marrow examination has an important role in staging and predicting prognosis in lymphoma Objective: To study the Incidence and Pattern of bone marrow infiltration in lymphoma, correlate bone marrow morphology with lymph node biopsy and assess the clinical prognosis according to bone marrow involvement. Methods: This is a 4-year retrospective study of 86 diagnosed cases of lymphoma with marrow infiltration. The clinical data were retrieved from the medical records and the bone marrow (aspiration and biopsy) slides, lymph node biopsy slides were reviewed. Results: A total of 135 cases of lymphoma were diagnosed on lymph node biopsy, out of which 106 cases (78.5%) were of Non - Hodgkin lymphoma and 29 cases (21.4%) were Hodgkin lymphoma. The overall incidence of marrow infiltration in lymphoma was 63.7 % (86/135). The incidence of marrow infiltration by NHL (71.7%) was higher when compared to HL (34.5%). Only 86 cases that had marrow infiltration by lymphoma were analyzed in this study. The most common type of NHL with marrow infiltration was follicular lymphoma (36.8%), followed by DLBCL (27.6%). In Hodgkin lymphoma, the equal incidence of marrow infiltration was found in Mixed cellularity, Lymphocyte - depleted and unclassified Classical Hodgkin lymphoma each accounting for 30%. The predominant pattern of marrow infiltration was-Mixed type (30.2%), followed by a diffuse pattern (27.9%). Morphological discordance between lymph node and trephine biopsy was seen only in 13 cases (15.1%), all of which were Non-Hodgkin Lymphoma. Conclusion: Overall marrow infiltration by Non-Hodgkin Lymphoma is higher compared to Hodgkin Lymphoma. The most common pattern associated with poor prognosis was the diffuse pattern.