The objective of this research was to determine the effect of black cumin seed oil (BCSO) on hematology, level of aspartat aminotransferase (AST)/alanin aminotransferase (ALT), level of ureum and creatinine, and also immune response in healthy subjects. This study applied a phase 1 of clinical trial. The 36 healthy subjects were divided into three groups, 12 subjects each group. Group I, subjects received 1 × 3 soft capsules of BCSO. Group II, subject received 2 × 3 soft capsules of BCSO and in groups III subject received 3 × 3 soft capsules of BCSO. Each soft capsule contained of 0.5 ml standardized BCSO. On the 21st day, the blood cell, level of ALT and AST and level of ureum and creatinine were measured. The average number of blood cells, levels of ALT/AST and level of ureum and creatinine then were been analyzed with one way ANOVA test. Statistical analysis was performed on 95% confidence level. The results showed that the administration of three doses of BCSO soft capsule did not increase number of blood cells, level of ALT/AST and level of ureum and creatinine (p>0.05). BCSO also did not affect number of CD4+ Th and CD4+CD25+ Treg cells and also expression of IFN-γ (p>0.05). The consumption of BCSO at three doses 1.5, 3, and 4.5 ml/d for 21 days in healthy subjects were tolerable and safety.