The purpose of the present work was to determine the plasma concentrations of fibrinogen and Von Willebrand Factor (VWF) as well as platelet aggregation, in an apparently healthy population of 306 men and 41 women, 33 to 65 years of age, workers of the national oil industry (PDVSA, Maracaibo), as a base investigation in a 5-year prospective national collaborative study. The participants were previously subjected to a thorough clinical examination with cardiovascular evaluation and laboratory tests. Clottable fibrinogen and VWF concentrations were determined in platelet poor plasma, the last one by immunoclectrophoresis, and a multimeric analysis of VWF was performed on those plasmas with concentrations higher than 150 U/dL by SDS agarose electrophoresis, followed by cellulose membrane transference. Platelet aggregation was studied in platelet rich plasma with no addition of stimulants and after collagen and ristocetin were added. Forty per cent of men and 65.8% of women, showed fibrinogen concentrations above 300 mg/dL (p < 0.01) and 12.2% of men and 15.4% of women had VWF values higher than 150 U/dL, with normal multimeric distribution. Fourteen individuals presented spontancous platelet aggregation and increased aggregation in 12 and 13 of them, after induction with collagen and ristocetin respectively. Comparing these findings with those of previous collaborative studies from other countries, the present results could mean that an important proportion of the population here studied, could be at risk for a future coronary event; however, as these are the base findings in Maracaibo, the significance of our results will be better evaluated at the end of the five year study.