The diagnosis of diabetic foot osteomyelitis is often difficult both clinically and radiologically with a delay in radiological sign occurrence and difficulties of imaging interpretation. Bone biopsy is known to be the diagnosis gold standard. However, if negative, the diagnosis of osteomyelitis cannot be excluded and this method is not harmless. An early diagnosis of osteomyelitis is necessary to start an antibiotic treatment in conjunction with conservative surgery. (99m)Tc-HMPAO labelled leucocyte scintigraphy performed in conjunction with bone scintigraphy significantly contributes to the diagnosis of osteomyelitis (sensitivity=100% and specificity > 95%). In case of osteomyelitis suspicion, after plain radiography, the (99m)Tc-MDP bone scintigraphy is the first step. If negative, osteomyelitis is unlikely. If positive, a (99m)Tc-HMPAO leucocyte scintigraphy should be performed in order to exclude or to confirm the diagnosis of bone infection.