Medical cannabis is increasingly being used in the treatment and support of several diseases and syndromes. The quantitative determination of active ingredients (delta-9 tetrahydrocannabinol, THC, and cannabidiol, CBD) in galenic oily preparations is prescribed by law for each produced batch. The aim of this work is to describe the organization of the titration activity centralized at three regional reference laboratories in Northern Italy. Pre-analytical, analytical, and post-analytical phases have been defined in order to guarantee high quality standards. A cross-validation between laboratories allowed for the definition of the procedures that guarantee the interchangeability between reference laboratories. The risk management protocol adopted can be useful for others who need to undertake this activity.