Double photon absorptiometry comparison was done of lumbar bone mineral content (BMC) values in 40 women with well-compensated non-insulin-dependent diabetes mellitus (type II) and on dietary and/or oral hypoglycemic treatment, and 35 age-matched non-diabetic women, to determine the presence and degree of osteoporosis in this type of diabetes by means of a highly precise and sensitive method. No difference between the two groups was noted as regards blood calcium, phosphorus, PTH and thyrocalcitonin, and urinary calcium and phosphorus. BMC, on the other hand, was significantly lower in the diabetics, both in L2,L3,L4 and in L4 alone. No significant difference could be discerned between patients on diet and those on drugs. It can thus be maintained that osteoporosis is a possible complication of type II diabetes and may appear even in the absence of its classical complications.