To directly correlate fluorine-18 fluoro-2-deoxy-D-glucose (F-FDG) uptake of the iliac crest, as determined with PET, with both spatially matched histological bone marrow parameters and laboratory markers in Hodgkin lymphoma patients without lymphomatous bone marrow involvement at bone marrow biopsy. This retrospective study included 21 patients with newly diagnosed Hodgkin lymphoma who underwent F-FDG-PET and who had a lymphoma-negative bone marrow biopsy of the right posterior iliac crest. F-FDG-PET maximum standardized uptake value (SUVmax) was measured in the right posterior iliac crest and correlated to histological bone marrow parameters (cellularity, myeloid/erythroid ratio, degree of fibrosis, and reactive T- and B-lymphocytes) and laboratory markers (hemoglobin, C-reactive protein lactate dehydrogenase, and leukocyte and thrombocyte counts) using Pearson's correlation coefficient (R) for Gaussian data or Kendall's tau (τ) for non-Gaussian data. There was a significant moderate correlation between F-FDG-PET SUVmax and cellularity of the iliac crest (R=0.519, P=0.016). Furthermore, there was a significant strong inverse correlation between F-FDG-PET SUVmax of the iliac crest and hemoglobin level (R=-0.661, P=0.001) and there was a significant moderate correlation between F-FDG-PET SUVmax of the iliac crest and C-reactive protein level (τ=0.441, P=0.007). All other correlations, including F-FDG-PET SUVmax of the right iliac crest versus reactive T- and B-lymphocytes in the bone marrow, were not significant. The observations suggest increased bone marrow F-FDG uptake to be caused by red marrow hyperplasia because of anemia in Hodgkin lymphoma. Increased bone marrow F-FDG uptake is unlikely to be caused by inflammatory bone marrow changes.