Several phases in the Bi-O system have been deposited by chemical vapor deposition on MgO(001) substrates. Bismuth iodide, BiI3, and oxygen were used as source materials. An experimental chemical vapor deposition stability diagram has been determined as a function of the deposition temperature and the [O-2]/BiI3] ratio. Depending on these parameters different phases such as alpha-Bi2O3, beta-Bi2O3, and Bi2O2.33, were deposited. At low deposition temperatures bismuth oxyiodides (BiOI or Bi5O7I) were also obtained. For suitable conditions the BiOI phase was found to grow epitaxially on the MgO(001) substrate with the two different orientations [100](MgO)//[100](BiOI) and [100](MgO)//[110](BiOI).