Background: Three key coumarinolignoids, cleomiscosins A, B, and C of Cleome viscosa seed origin in particular ratio, are a proven hepatoprotective agent known as Cliv-92. Objectives: However, the bioavailability and pharmacokinetics of Cliv-92 are still not clear. The present study is the first validated method which deals with the assay of Cliv-92 in mouse plasma. Methods: Single-step sample preparation meets the criteria of recovery (80%–93% with relative standard deviation [RSD] 2.14%–4.80%). Reverse-phase high-performance liquid chromatography with photodiode array detection has resulted into acceptable separation and sensitivity of three structurally similar cleomiscosins – A, B, and C of Cliv-92. The analysis involved a binary gradient of mobile phase and flow rate. Quantification was done at peak area at 326 nm using linear regression curve (r2 > 0.999). The precision (0.46%–2.68% RSD) and accuracy (±2.09% bias) of Cliv-92 determination in plasma complied the criteria of the current international guidelines. We have also evaluated the matrix effect on sensitivities by spiking method. Limit of detection and limit of quantification in mouse plasma ranged between 0.13–0.24 μg/ml and 0.41–0.74 μg/ml. Results: Pharmacokinetic parameters were studied after intravenous bolus administration of Cliv-92 at 10 mg/kg dose in mice. Blood samples were collected at a predefined time up to 24 h post-injection. The Cliv-92 plasma half-life (t1/2) was 2.77 h, and the clearance was estimated as 2.38 L/h/kg. Conclusion: The method is simple, sensitive, and accurate for the determination of plasma concentration of coumarinolignoids. The present preclinical pharmacokinetic study of coumarinolignoids has been anticipated in clinical studies with scaling techniques.