The reaction of hydrazoic acid, HN3, with trimethylgallium to produce thin-film gallium nitride under very-low-pressure chemical vapour deposition (VLPCVD) conditions is described. Data are presented which show that at 10–6 mbar the product GaN is crystalline and strongly oriented on the substrate sapphire (0001) crystal face. Some potential advantages of using HN3 rather than the conventional precursor NH3, for nitride film production, are mentioned.