The X-ray crystal structures of threeβ-blockers of the phenylethanolamine (PEA) class have been determined by single crystal techniques. They are (I): (±)-2-(2-bromo-3,4-dimethoxyphenyl)-2-hydroxy-N-isopropylethylamine hydrochloride; (II): (±)-2-(3-bromo-4,5-dimethoxyphenyl)-2-hydroxy-N-isopropylethylamine methylsulphonate; (III): (±)-2-(2-bromo-4,5-dimethoxyphenyl)-2-hydroxy-N-isopropylethylamine hydrogen oxalate. A conformational energy map of a partially hydrated model cation as a function of the principal torsion angles τ1 and τ2 shows the “transperpendicular” conformer (τ1≈90°, τ2≈180°) to be the most stable. This conformation is adopted by cations of (II) and (III) in their crystals, but for (I), τ1=52.3(6)° is observed. Non-bonded pharmacophoric distances lie within the expected ranges.