Cannabis is a tobacco-like greenish or brownish material consisting of the dried flowers, fruiting tops and leaves of the cannabis plant. The plant Cannabis sativa is the source of both marijuana and hashish. Both drugs are usually smoked. Their effects are similar: a state of relaxation, accelerated heart rate, perceived slowing of time, and a sense of heightened hearing, taste, touch, and smell. These effects can differ, however, depending on the amount of drug consumed and the circumstances under which it is taken. This is analytical a case control study, aimed to investigate the effects of cannabis addicted on blood cell count, of Sudanese addict. The study conducted in al-Hayat health care center, during the period from September to October, 2018. Forty cannabis abuser and twenty healthy volunteers, were enrolled in this study after a written consent had been obtained from them, the data were collected using a non-self-questionnaire and laboratory measurement. The distribution of cannabis abusers according to age (28±10). The secondary educational qualification recorded the highest frequency (26), and (3) for technical qualification. Duration of (3-5) years of cannabis addicts recorded the highest frequency (23), and (9-11) years recorded the lowest frequency (4). The distribution of other substances addicted with cannabis indicated that cigarette recorded the highest frequency (14), and tobacco recorded the lowest (1). The abuser jobs indicated that casual jobs recorded highest frequency (23), and permanent job. Hemoglobin concentration was significantly higher in cannabis abuser compared with control group (14.0±2.8 vs 12.6±2.6), (P value <0.04). Platelet count was significantly lower in cannabis abuser compared with control (260.0±69.29 vs 327.9±70.14), (P value =0.01). Neutrophils count was significantly lower in Cannabis abuser group compared to the control group (35.09±9.3 vs 40.3±12.6),(P value = 0.02) WBCs, RBCs, HCT, and RDW-SD values were not influenced significantly by cannabis addiction. Cannabis causes an increase in carboxy hemoglobin, a resultant increase in myocardial oxygen demand, decrease in oxygen supply as well as an induction of platelet.