After chronic administration of crude Cannabis resin (CCR), (20 mg/kg and 40 mg/kg) to Spraque-Dawley albino rats for 21 days, the changes in various haematological indices such as packed cell volume (PVC), total leukocyte count, differential leukocyte count, red blood cell (RBC) count, absolute lymphocyte count, monocyte count, neutrophils and eosinophil counts were evaluated. The results show that the haematological indices such as erythrocytic and leucocytic counts were not significantly (P

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... 0.05) affected by the treatment with the crude cannabinoid resin treated animal groups for the first two weeks of treatment. However in the third week, results showed significant increases (P < 0.05) in the above mentioned indices while eosinophils disappeared from the blood of treated groups. It can be concluded from this study that chronic administration of CCR at high doses (above 20mg/Kg) to rats has slight haematotoxic potentials.