The multinuclear NMR spectral data for an homologous series of tertiary phosphines, R3‐nP(NMe2)n, aminophos‐phonium ions, [R3PNR′R″]+, and phosphonium ions, [R4‐nPMe]+, where R = Me, Et, n‐Pr and Ph, R′ and/or R″ = H, Me and n = 0 and 1 are reported and discussed. Quaternization by alkylation or chloramination causes an increase in the 31P chemical shift (Δ δP is positive), a decrease in the 13C chemical shift (Δ δC is negative) for all carbons, an increase in the magnitudes of 1J(PC), 3J(PC), 3J(PNCH) and 2J(PCH) and a decrease in the magnitude of 2J(PC). Substitution of a Me2N group for an alkyl or aryl group produces an increase in the 31P chemical shift and in the magnitude of 1J(PC). α‐ and β‐deshielding and γ‐shielding effects are noted in the 13C NMR spectra and β‐deshielding and γ‐shielding effects are noted in the 31P NMR spectra with substitution on the phosphorus and nitrogen atoms. Copyright © 1987 John Wiley & Sons Ltd.