Some sterically protected 2-(1-azulenyl)- and 2-(2-azulenyl)-1-(2,4,6-tri-t-butylphenyl)-1-phosphaethenes were prepared from the corresponding silylphosphide and 1- and 2-formylazulenes by the phospha-Peterson reactions. The crystal structure of 2-(6-isopropyl-1-azulenyl)-1-(2,4,6-tri-t-butylphenyl)-1-phosphaethene was determined by the X-ray analysis.