A sensitive, accurate, and robust high-performance thin-layer chromatographic (HPTLC) method has been established for simultaneous analysis of wedelolactone (WED) and asiaticoside (ASI) in Eclipta alba and Centella asiatica Linn., respectively. Chromatography was performed on silica gel with toluene-acetone-methanol-formic acid 3.0:2.0:2.0:0.05 (υ/υ) as mobile phase. Densitometric scanning at 317 nm for WED and at 530 nm, after derivatisation with 10% methanolic sulphuric acid, for ASI was used. The method was validated in accordance with the guidelines of the International Conference on Harmonization (ICH). RF values of 0.26 and 0.75 were obtained for ASI and WED, respectively. The linear ranges were 50–250 and 150–550 ng per band for WED and ASI, respectively, with good correlation coefficients (r2 = 0.999 and 0.9989, respectively). Accuracy was 99.29% and 99.45% for WED and ASI, respectively. The method was found to be precise, robust, and suitable for routine quality-control analysis of plant extracts and polyherbal formulations.