Objectives: To determine risk factors of pre-hypertension and hypertension in a cohort of 1247 rural Tanzanian women before conception. Methods: Demographic and socioeconomic data, anthropometric measurements, past medical and obstetric history and other risk factors for pre-hypertension and hypertension were collected using a structured questionnaire. Multiple logistic regression analysis was used to evaluate the associations between anthropometric indices and other risk factors of pre-hypertension and hypertension. The predictive power of different anthropometric indicators for identification of pre-hypertension and hypertension patients was determined by Receiver Operating Characteristic curves (ROC). Results: The median (range) age was 28.0 (18–40) years. The age-standardised prevalences of pre-hypertension and hypertension were 37.2 (95% CI 34.0–40.6) and 8.5% (95%CI 6.7–10.8), respectively. Of hypertensive patients (n = 98), only 20 (20.4%) were aware of their condition. In multivariate analysis, increasing age, obesity and haemoglobin levels were significantly associated with pre-hypertension and hypertension. Conclusion: Despite a low prevalence of hypertension, over one third of the women had pre-hypertension. This poses a great challenge ahead as pre-hypertensive women may progress into hypertension as they grow older without appropriate interventions. Obesity was the single most important modifiable risk factor for pre-hypertension and hypertension.