Hematological parameters are affected by different factors that include age, sex, smoking, ethnicity, and environmental altitude. It has been justified that each population must establish its own normal reference intervals to be used in clinical assessments and interpretations. Hematological reference intervals for adults from the Gaza Strip-Palestine have never been addressed. Therefore, this study was designed and aimed at the establishment of normal blood cells reference intervals for healthy adults at the Gaza Strip-Palestine. This study involved 89,491 apparently healthy individuals (from both sexes and from the different governorates of the Gaza Strip) who were referred to the Thalassemia Central Laboratory during the period from September 2000 until February 2008. Complete blood counts were performed. Subjects were categorized into subgroups according to gender, smoking habit, and age (15-18, 19-45, and >45 years old). For each subgroup, descriptive and comparative statistical analysis was performed for hematological parameters. The results showed substantial differences between males and females, between smokers and nonsmokers, and between the different age groups. Moreover, reference intervals derived from our population are markedly shifted downward as compared with Western European and American populations. It was concluded that separate and region-specific reference intervals based on gender, smoking, and age for the Palestinian population at the Gaza Strip should be generalized for clinical laboratories and clinical practitioners, which could help in interpreting laboratory hematological tests more specifically, and potentially develop the quality of medical care provided to patients.