Two hundred, and ninety-five male Finnish concrete reinforcement workers, aged 19-64 years and engaged in heavy physical work including prolonged stooping, were clinically examined in a cross-sectional study. A history of sciatica was reported by 42% of the men, and a history of lumbago by 33%. The prevalence of the reported experience of sciatica and lumbago doubled in the two decades from age 25-34 onward. Half of those with a history of sciatica had also experienced lumbago; two-thirds of those who reported a history of lumbago had also suffered from sciatica. Back symptoms during an ordinary workday were reported as follows: ache 51%, fatigue 47%, stiffness 41% and sharp pain 13%. The correlation between the four symptoms was slight. Ache (X^2=23.5, P＜0.001) and stiffness (X^2=12.0, P＜0.001) were more common in workers with a history of sciatica than in workers without a history of lumbago or sciatica. In the analysis of the results for a possible effect of reinforcement work on back morbidity, the occurrence of back symptoms and syndromes was not found to be associated with length of reinforcement work, while comparison of a history of low-back pain syndromes between reinforcement workers and computer technicians showed experience of sciatica to be somewhat more common in the reinforcement workers (X^2=5.2, P＜0.05).