Alterations in water and electrolytes content of serum and tissues have been indicated in the management of hypertension amongst others. This study aims to evaluate the diuretic, saliuretic and natriuretic effect and acute toxicity of a crude Aqueous Extract of Cola nitida (AECONS) on urinary parameters over a 6 h (at 2 h interval) in Wistar Albino rats and their serum and kidneys after a three weeks’ dose regimen. To evaluate the diuretic activity of the plant, Albino rats were divided into five groups. The control group received normal saline (10 ml/kg), the reference group received furosemide (20 mg/kg) and the test groups were administered different doses (i.e., 400, 600 and 800 mg/kg) of the crude extract by oral route (gavage) respectively. Student t-test and One-way ANOVA was used for the statistical analysis and p-values less than 0.05 were considered statistically significant. We observed significant diuretic, saliuretic and natriuretic effects in the treated groups in a dose dependent manner. However, urinary pH remained unchanged during the study except in the 800 mg/kg group. The diuretic index values showed good diuretic activity of the crude extract. The Lipschitz values demonstrated in the crude extract, at the dose of 600 mg/kg showed two-fold diuretic activity when compared with furosemide and control groups. Hence, this study confirms the significant diuretic, natriuretic and saliuretic activity of the AECONS. During the measurement period of the study (6 h) which provides empirical basis for its pharmacological action in the treatment of health conditions.