Insight into the unique structure of layered double hydroxides has been obtained using a combination of X-ray diffraction and Raman spectroscopy. Indium-containing hydrotalcites of formula Mg4In2(CO3)(OH)12· 4H2O [2:1 In-LDH (layered double hydroxides)] through to Mg8In2(CO3)(OH)18· 4H2O (4:1 In-LDH) with variation in the Mg : In ratio have been successfully synthesized. The d(003) spacing varied from 7.83 Å for the 2:1 LDH to 8.15 Å for the 3:1 indium-containing layered double hydroxide. Raman spectroscopy complemented with selected infrared data has been used to characterize the synthesized indium-containing layered double hydroxides of formula Mg6In2(CO3)(OH)16· 4H2O. Raman bands observed at around 1058, 1075 and 1115 cm−1 are attributed to the symmetric stretching modes of the CO32− units. Multiple ν3 CO32− antisymmetric stretching modes are found at around 1348, 1373, 1429 and 1488 cm−1 in the infrared spectra. The splitting of this mode indicates that the carbonate anion is in a perturbed state. Raman bands observed at 690 and 700 cm−1 assigned to the ν4 CO32− modes support the concept of multiple carbonate species in the interlayer. Copyright © 2010 John Wiley & Sons, Ltd.