Electronic circular dichroism (ECD) spectroscopy is widely used to assign the absolute configuration (AC) of chiral molecules. ECD arises from the interference between electric and magnetic transition dipole moments and therefore, is strongly dependent on the spatial position of chromophores and insensitive to the distant molecular groups. Moreover, for compounds with multiple chromophores and complex stereochemistry, the interpretation of ECD data in terms of AC is an arduous task. Thus, the use of ECD spectra is recommended in conjunction with other analytical and computational methods for the AC determination. The standard method used in combination with ECD spectroscopy is a single crystal X-ray crystallography. However, there may be experimental difficulties in growing crystals, especially in the case of supramolecular complexes. Moreover, differences between solid and solution structures can cause problems upon comparison of experimental and simulated data on the basis of the crystallographic structure ECD spectra. Likewise, ECD studies are often combined with NMR. The NMR data alone, such as NOE and J-coupling constants, provide useful information about a three-dimensional molecular structure and its low-energy conformers. Furthermore, NMR enables the determination of the relative configuration of a molecule as well. These means contribute to elucidation of the entire molecules' structure and stereochemistry. However, the AC determination by NMR is a complicated task requiring special methodologies, such as chiral derivatization. Recently, it has become a widely accepted practice to rationalize the experimentally measured ECD spectra by using the time-dependent density functional theory (TD-DFT) approach. This allows not only to confirm the experimental observations, but also to explain the origin and mechanism of chirogenesis. However, the critical requirement for theoretical predictions of chiroptical properties, including ECD spectra, is a correct chemical structure of the compound of interest. Thus, in flexible molecules with multiple chiral centers this becomes a complicated and time-demanding task. Moreover, the corresponding conformational search, determination of conformer populations, and ECD spectra simulation have their limits of accuracy. Porphyrins have featured widely in studies on chirogenesis and sensing and are suitable test beds for validating analytical tools. In this work the ECD spectra of a sterically hindered hexacationic P ([5,10,15,20-tetrakis(2aminiumphenyl)-2,3,7,8,12,13,17,18-octaethylporphyrin) complex with two enantiomers of camphorsulfonic acid (CSA) as chiral guests (Figure ), were experimentally and computationally studied in dichloromethane and chloroform. For conformational analysis the NMR and X-ray crystallographic data from our previous work were used. We investigated the influence of various geometric factors, such as the position of (R)-CSA, distortion of porphyrin plane, and orientation of both aromatic and non-aromatic peripheral porphyrin substituents on the ECD spectra. Special attention was given to consider the origins of potential mistakes in spectral simulations, such as a lack of significant conformations and accidental agreement of the experimental and theoretical spectra.