Poly(butyl cyanoacrylate) was synthesised using triphenylphosphane and pyridine initiators. Matrix-assisted laser desorption/ionisation time of flight mass spectrometry and NMR spectroscopy were used to confirm that the initiator remains as a chain end group. The prepared polymers were subjected to thermal degradation and re-analysed with results that show the loss of the initiator end group for the pyridine-initiated polymer, but not for that initiated with triphenylphosphane. Pyrolysis gas chromatography-mass spectrometry was used to observe the presence of the pyridine initiator in the volatile degradation products.