A method for the removal of nitrogen compounds from FCC feed or from catalytically cracked distillates including FCC cycle oils by using formaldehyde to selectively couple organic heterocyclic nitrogen species in the FCC feed or FCC distillate to form higher boiling coupling products out of the boiling range of FCC distillate. Removal of the nitrogenous compounds improves the operation of subsequent hydrodesulfurization steps needed for the distillate fraction to conform to low sulfur standards. The formaldehyde is preferably used in the form of paraformaldehyde. The reaction between the nitrogenous compounds in the cycle oil fraction with the formaldehyde is conveniently carried out in the cycle oil pumparound circuit of the FCC main column.