In the late 1980s, he created a disproven cancer treatment known as "Di Bella therapy" that precipitated an international controversy.

During the late 1980s, Di Bella developed a cocktail of drugs, vitamins and hormones (Melatonin, ACTH and Somatostatin) which he argued would be useful in fighting cancer.

Following national exposure in 1997 and 1998, several cancer patients from around Italy traveled to his clinic seeking access to his "miracle cure".

[5] The final rejection of Di Bella's method was expressed in a letter (written on 30 December 2005) by the chairman of the Board of Health, Mario Condorelli, to Health Minister Francesco Storace: "The working group of the Board of Health considers that it has no evidence of the effectiveness of "multitherapy Di Bella" and therefore does not recommend a new clinical trial; this could be not only ineffective but also harmful to the patients by denying them (or procrastinating) access to anti-cancer drugs of proven effectiveness.

"[9] Physician Silvio Garattini described Di Bella's therapy for cancer as a "totally irrational association of drugs supported by absolutely no scientific evidence or data whatsoever.