The 24-year-old winger has been linked with the Naples club for much of the transfer window and completion of the deal appears close.
Lozano was mobbed by a group of Napoli supporters shortly after arriving at an airport in Rome, posing for photographs with fans displaying club merchandise.
A direct, goalscoring winger, Lozano has enjoyed two excellent seasons with PSV in the Eredivisie.
Having joined from Pachuca in 2017 after building a fine reputation for himself at home in Mexico, Lozano seamlessly settled into Dutch football.
He scored 17 league goals and added eight assists in his first campaign, resulting in speculation linking him with more illustrious European clubs, such as Manchester United.
Although Lozano was not able to inspire PSV to the title again last term, he proved his debut season was no fluke by accumulating the same number of goals and assists.
Also known for his blistering pace, Lozano has been capped 35 times by Mexico and is generally regarded as one of the country's most talented exports since Real Madrid icon Hugo Sanchez.
Lozano will reportedly undergo a medical on Wednesday.