The objective of the work was to study felodipine distribution in warm-blooded animals (rats). The methods of TLC, GC-MS, and UV spectrophotometry were used in the experiments. A lethal dose of felodipine (1.05 g/kg) preliminary suspended in water was introduced intragastric into test animals (male rats of the Wistar line). The analyzed compound was isolated from solid tissues and blood of the animals with acetone, purified by the solvent replacement, and by macrocolumn chromatography with the Silasorb S-18 sorbent of 30 µm and polar eluent, acetonitrile—water (7:3). The analyte was identified by chromatographic behavior in a thin sorbent layer, retention time, and a set of positive ions in its mass spectrum, as well as by the UV spectrum. The analyte was quantitatively detected in biological matrices using UV spectrophotometry. The method was validated by the criteria of linearity, selectivity, accuracy, precision, limits of detection, and quantitative determination. The predominant content of felodipine was detected in tissues of the stomach (312.303±25.980 µg/g), small intestine with its contents (93.235±12.310 µg/g), stomach contents (80.072±8.510 µg/g), and in the spleen (26.083±1.758 µg/g).