BACKGROUND: Patients with diabetic foot ulcers (DFU) and chronic limb-threatening ischemia (CLTI are at higher risk for major amputations and mortality. The aim of this study was to assess the safety and cost-efficacy of intramuscular injection of autologous monocyte-rich PRP platelet-rich plasma Tropocells® PRP (Estar Medical, Holon, Israel) in diabetic patients with chronic limb-threatening ischemia (CLTI) in which revascularization was not feasible. METHODS: a retrospective study was carried out on a series of patients with type 2 diabetes, grade Texas 3C or D DFU, and CLTI. All patients had undergone at least a previous revascularization and were allocated to a surgery waiting list for major amputation. According to the data provided by the manufacturer (https://www.zuccatobiotech.it/index.php/prodotti/tropocells), the monocyte-rich PRP kit obtained a platelet-rich plasma with a high concentration of peripheral blood mononuclear cells (with a proportionately lower amount of lymphocytes), a low concentration of neutrophils and an almost complete depletion of red blood cells. All patients underwent a procedure of local infiltration of autologous mononuclear cells through multiple perilesional and intramuscular injections of 10 mL PBMNC suspensions (0.2–0.3 mL in boluses) performed below the knee along the relevant vascular axis (anterior tibial artery and posterior tibial artery) at intervals of 1–2 cm and to a mean depth of 1.5–2 cm, using a 21 G needle. The procedures were performed according to the instructions of the manufacturer and were repeated at least two times (maximum 3 times) at intervals of 30 days. The principal endpoint was a composite of TcPO2 values at the first toe ≥30 mmHg and/or TcPO2 increase of at least 50% from baseline and/or ulcer healing. Secondary endpoints were individual components of the primary endpoint, quality of life, any adverse events, and direct costs. All the endpoints were evaluated at 26 weeks. RESULTS: Out of 21 enrolled patients, 13 (61.9%) reached the primary endpoint, whereas three patients underwent a major amputation, and two patients died. The median TpCO2 was significantly increased, and pain was significantly reduced. The overall mean and median cost per patient were 9,255±7,328€ and 4,001 [2,991;7,565]€, respectively. CONCLUSIONS: the use of PBMNCs implants in patients with DFU and no-option CLTI seems to be efficacious in reducing the risk of major amputation and improve ulcer healing.