In order to clarify the influence of asbestos on the health of the workers engaged in works in which they use materials made of asbestos, the environmental investigation and their health examination were carried out in a shipyard where such materials have been used increasingly in recent years. The clarified facts and the conclusions thereby were as follows: 1) At the shipbuilding plant, lagging workers and carpenters were engaged in asbestos-handling works. The environmental airs around the lagging workers and carpenters were measured and proved to have 4 and 55.4 fibres/c㎥ of asbestos in maximum respectively. Carpenters were engaged in works cutting several kinds of noninflammable board and sound proofing board. For the works, large quantity of asbestos dust was generated. It was observed that the lack of experience and knowledge for asbestos-works had delayed the measures to protect the hazards. The need of the establishment of the countermeasures against general dust hazards as well as asbestos dust hazards must be urgently recognized. 2) The asbestos-handling works might influence on other works which were carried out simultaneously in the same new ship under construction. The prevention of asbestos hazards for other workers must be considered. 3) Chest X-ray examination explored that 35.7% of lagging workers and 31.0% of carpenters had pneumoconiosis. Asbestos bodies were found with high frequency in both groups. The facts supported that they had suffered from the exposure of asbestos substantially. Between the two groups, differences of X-ray findings were observed; irregular small opacities in lagging workers and irregular small opacities as well as compound small opacities in carpenters. They were thought to be due to the differences of kinds of dust inhaled. 4) The countermeasures against the cutting procedure of asbestos cloth and pipe covering in the case of lagging workers, and the dust generated in high density by electric rotary saw in the case of carpenters are the urgent need to be established.