The synthesis and study of a series of pseudohalides of boron subphthalocyanine (BsubPc) are reported. Each pseudohalide has been compared to the more common chloride and bromide of BsubPc, and we have found that most react slower under standard phenoxylation and hydrolysis conditions. Three pseudohalides (TsO-BsubPc, MsO-BsubPc, and BsO-BsubPc) do not hydrolyze at all even after prolonged periods of time in the presence of water. Single crystals of TsO-, MsO-, and ClsO-BsubPc were obtained, and their structures were unambiguously determined.