In 100 patients with mainly chronic low back pain (LBP) signs and symptoms were evaluated prospectively and without preconceived expectation of particular findings. Two clinical syndromes were distinguished, both characterized by 'typical local tenderness' and associated with specific clinical features; these syndromes, described previously in the literature but receiving scant attention, were named the greater trochanteric pain syndrome (trochanteric bursitis) and the iliac crest pain syndrome (iliolumbar syndrome), and occurred in 35% and 43% of the patients, respectively. The recognition of these syndromes may enable us to study aetiology, prognosis, and therapy of LBP in more homogeneous groups of patients.