The substitution reactions of the monospiro and geminally disubstituted cyclotriphosphazene derivatives N₃P₃Cl₄R₂ (R₂ = OCH₂(CF₂)₂CH₂O (1a), SPh (1b), OCH₂CH₂CH₂O (1c), NHPh (1d), OCH₂CH₂CH₂NH (1e), NHBu^t (1f)) with two secondary amines (pyrrolidine and dimethylamine) were carried out to investigate geminal or non-geminal directing effects in mixed substituent cyclophosphazenes. The relative amounts of isomeric products, geminal and non-geminal trans or cis, was established quantitatively from the ³¹P NMR spectra of the reaction mixtures. Although secondary amines generally follow a non-geminal pathway in the reactions with hexachlorocyclotriphosphazene, in this work, the reactions of two different secondary amines with some N₃P₃Cl₄R₂ (R₂ = OCH₂CH₂CH₂NH, NHPh, NHBu^t) derivatives lead to the formation of geminal products. We have shown that this observation depends on the electron-donating properties of the PR₂ groups. Isolated compounds were analyzed by standard techniques such as elemental analysis, mass spectrometry, and ¹H and ³¹P NMR spectroscopy. The structures of compounds for which suitable crystals could be obtained were characterized by X-ray crystallography.