Acute renal dysfunction has been described as a feature of acute overdoses of the nonsteroidal anti-inflammatory drugs benoxaprofen, fenoprofen, ibuprofen, mefenamic acid, piroxicam, suprofen, and zomepirac. The cases reported here include renal impairment after acute overdoses of another three nonsteroidal anti-inflammatory drugs: diclofenac (one case), naproxen (two cases), and sulindac (five cases). The eight patients presented with lumbar pain and oliguria and had protein and erythrocytes in the urine. Serum creatinine was increased to a maximum of 190-932 mumol/L. Renal impairment was generally transient but in one case was treated by hemodialysis and one by continuous arterio-venous hemofiltration dialysis. In all cases of significant acute overdose of nonsteroidal anti-inflammatory drugs, the risk of acute renal dysfunction must be considered.