Although the major pollution problem in cement factories is cement dust emission into the factory environment (ILO, 1999), there is paucity of data on the effect of cement dust exposure in cement factory workers in Nigeria. Evidence from experimental animals suggests that cement dust may be toxic to the liver (Kanta et al., 1986) and bone (Pond et al., 1982). We hypothesized that such liver and bone lesions may also occur in man. Consequently we have measured haematological, liver and lung function parameters in the workers of the Cement Factory of Northern Nigeria, Sokoto. Randomly chosen factory workers [n=56; years of exposure= 10.2 ± 5.6 (mean ± SEM) years] and an unexposed but matched group (n=96) were studied following informed consent. Data collection was effected by way of a structured questionnaire to determine use of protective gears e.t.c. Vital capacity (VC) and forced expiratory volume in 1 second percent (FEV₁%) were measured at ATPS (ambient temperature and pressure saturated with water vapour). 10ml of blood was drawn. Some was anticoagulated and used to measure haematological parameters using the Quantitative buffy coat (QBC) II machine. Serum was obtained from the remaining and used to estimate the liver function parameters using the RANDOX test kits. Results are expressed as mean ± standard error of mean (SEM). Statistical analysis was carried out using the unpaired student t test. P<0.05 was taken as statistically significant. Questionnaire responses indicated that protective gears were used by all workers. The VC [3.7 ± 0.5; versus 4.1 ± 0.5L; P<0.001], FEV1% [78.4 ± 3.1; versus 89.0 ± 1.5%; P<0.005], haemoglobin concentration [12.1 ± 0.4; versus 14.1 ± 0.2g/dl; P<0.0005] and packed cell volume [39.4 ± 6.9 versus 42.6 ± 4.6%; P<0.02] were significantly lower in cement factory workers than in matched controls while the white cell [8.5 ± 0.6 versus 7.3 ± 0.2 (x^109/l); P<0.05] and platelet counts [281.9 ± 20.3 versus 185.6 ± 5.6 (x^109/l); P<0.001] were significantly higher. The serum liver function tests showed no significant difference except alkaline phosphatase [32.9 ± 0.8 versus 53.9 ± 7.2(U/l); P<0.01] which was significantly lower in the cement factory workers than in the control subjects. The results of the present study suggest that chronic exposure to cement dust may have deleterious effects on the lungs, the haemopoetic system and the liver.