BACKGROUND: Hypertension is increasingly prevalent globally. Pre-hypertension is associated with cardiovascular mortality but often overlooked, particularly in sub-Saharan Africa, where healthcare resources are limited. The Dietary Inflammatory Index (DII) evaluates the inflammatory potential of dietary patterns, which may influence pre-hypertension risk. This study aims to investigate the relationship between DII and pre-hypertension among adults, highlighting the need for effective dietary interventions. METHODS: A muti-center cross sectional study involving 284 adult non-hypertensive patients was conducted in Nigeria and the Democratic Republic of Congo (DRC). Dietary habits were assessed using the Dietary Inflammatory Index (DII), while pre-hypertension was assessed using auscultatory method with a sphygmomanometer and stethoscope, following recommended guidelines. Data analysis included descriptive statistics, chi-square tests, and logistic regression. RESULTS: Of 279 respondents who completed the study, 56.3% had pre-hypertension while 48.4% had high DII (pro-inflammatory). Prevalence varied across age groups, ethnicities, and study sites. Although, DII did not significantly predict pre-hypertension in this study, underweight (aOR = 0.26, CI = 0.07-0.98, p = 0.047), and younger age (aOR = 0.25, CI = 0.08-0.74, p = 0.013), were independently associated with reduced pre-hypertension risk. CONCLUSION: Pre-hypertension is common among adults in Nigeria and DRC. Dietary inflammatory index did not influence pre-hypertension
however, age and BMI are critical factors that influence the risk of pre-hypertension.