Objectives: To estimate the prevalence of pre-hypertension and its association with some selected cardiovascular risk factors among the Omani adult population in the primary healthcare setting. Method: A cross-sectional study involving a sample taken from a National Screening Program of chronic non-communicable diseases in primary healthcare institutions, Sohar city, Sultanate of Oman (July 2006 - December 2007). Inclusion criteria included Omanis aged 40 years or above residents of Sohar city attending primary healthcare institutions not previously diagnosed with diabetes mellitus, hypertension, or chronic kidney diseases. Descriptive statistics were used to describe the demographic, physical and metabolic characteristics. Univariate analysis was used to identify the significant association between the characteristics and normal blood pressure, pre-hypertension and hypertension. Chi-squared test was used for categorical variables analysis and independent t-test was used for continuous variables analysis. In order to examine the strength of significant associations, the multinomial logistic regression analysis was used. Results: There were 1498 participants, 41% were males and 59% were females. Overall, pre-hypertension was observed in 45% of the total study population (95% CI: 0.422 - 0.473). There were more males affected than females (46% versus 44%). About 34% of the total study population was hypertensive. The multinomial logistic regression analysis revealed that an increase of one unit of age, body mass index, fasting blood glucose and total blood cholesterol, were significantly associated with higher risk in both pre-hypertension and hypertension. High odds ratio of pre-hypertension and hypertension was found with the total blood cholesterol. Conclusion: The prevalence of pre-hypertension was high among the Omani adult population. The determinants of pre-hypertension in this research age, body mass index, fasting blood glucose and total blood cholesterol. A cost-effectiveness study about the management of pre-hypertension within primary healthcare is significant in the future health system service strategies.