Laboratory diagnosis of many diseases provides great help to the clinicians to decide proper treatment. Accurate values of normal range for immunological parameters are essential inquiry for précised results. The present study aimed at quantitative determination of Immunoglobulin IgM, IgA, and IgG level as well as rheumatoid factor among Saudi blood donors. 364 donors were enrolled in this study, serum specimens were collected and utilized for nephlometeric quentitation of the immunoglobulin's and RF using automated machine (BN prospect – semins). The donors were categorized into three group's smokers, non smokers, athletic, non athletic, married and unmarried. Results showed that Ig level is higher in married than unmarried, and in athletic than non athletic. While the level was lower in smokers than non smokers. RF was higher in married and in smokers than non smokers, where the level was lower in athletics than non athletics. Based upon this study, we highly recommend the implementation of research project for normal ranges in KSA of all immunological, Bio chemical and serological parameters to get our own national normal ranges versus the international ranges.