Scope: The intestinal epithelium is a selective barrier that facilitates the absorption of essential compounds from the diet. In this sense, prediction of the oral bioavailability of bioactive compounds, such as maslinic acid, has to consider not only the uptake but also the subsequent metabolism. Therefore, the aim of the present work was to investigate in the rat: 1) the mechanism of transport of maslinic acid in the apical membrane of enterocytes, 2) the bioavailability after oral and intravenous administration and 3) the metabolism in plasma and urine. Methods: Maslinic acid absorption was studied with an in vivo perfusion technique. Overnight fasted Sprague-Dawley rats (272-300 g) were anesthetized with ketamine (90 mg/kg) and xylacine (10 mg/kg). A 20-cm jejunal segment was perfused with a phosphate buffer containing 13 concentrations of maslinic acid from 0.01 to 20 µM. In each experiment, five different concentrations were used in triplicate at a flow rate of 3.6 mL/min for 5 minutes with re-circulation. For the bioavailability study, maslinic acid was administered orally (50 mg/kg) and intravenously (1 mg/kg). Blood was withdrawn at different time points over 24 hours through the saphenous vein. Plasma was extracted with ethyl acetate before being injected to an LC-APCI-MS. Metabolite profile was characterized by LC-APCI-LTQ-Orbitrap-MS in plasma and urine obtained at 45 min after oral administration. Results: Kinetic analysis with the Enzfitter software showed that data was best adjusted to a first order equation with an apparent diffusional constant (Kd) of 7.01 μL/5 min/mg dry weight, without the participation of an active transporter, as evidenced with perfusions with dinitrophenol (200 µM). Plasmatic data analyzed with the WinNonlin software was best fitted to a bicompartmental model with first order absorption and lineal elimination processes. The pharmacokinetic parameters indicated a relatively rapid absorption (Ka = 0.52 1/h) with a maximum concentration of 4.03 µM at 30 min, and an oral bioavailability of 5.13%. Screening for metabolites in plasma yielded four monohydroxylated derivatives (M1a−M1d), one monohydroxylated and dehydrogenated metabolite (M2), and two dihydroxylated and dehydrogenated compounds (M3a-M3b). In urine, M1a, M1d, M2, and M3a were detected. All the derivatives came from phase I reactions without the presence of phase II metabolites. Analysis of the relative abundance showed a reduced metabolism since maslinic acid was the most prevalent compound in plasma (82%) and urine (74%). Conclusion: Maslinic acid is taken up by the enterocytes by simple diffusion with low Kd value and has a low oral biavailability that can be attributed to the intestine and not to metabolism.