The objective of this study was to identify and describe the actions of Brazilian senators in the field of public health in 1995 and 1996. We also sought to determine if profession, regional background, or political party influenced the senators' actions. The actions were divided into three types: legislative (proposal and review of bills and petitions); supervisory (information requests to the executive branch and the establishment of inquiry committees and other special committees); and parliamentary (speeches). The data were collected from two databases maintained by the Senate, namely MATE and DISC. Of the 89 senators who were in office during the study period, 76 were involved with public health issues. Of the total of 667 actions studied, there was a predominance of speeches (43% of all actions), most of them responding to news reported by regional or national media. Supervisory activities were limited (5% of all actions were information requests). The subjects dealt with most frequently were health policies (30%), drugs (9%), regulation of health professions (8%), disease control (7%), and worker health (6%). Concerning the professions of the senators, the most frequent categories were physicians, teachers, and journalists. The senators representing the North and Northeast regions performed 62% of the actions and were involved with almost all the health subjects. Although 43% of the actions were carried out by liberal and right-wing senators, the senators from socialist and labor parties had a stronger proportional participation (both in terms of senators involved and actions performed). It is interesting to note that socialist and labor senators showed minimal involvement in the issue of worker health. The predominance of speeches as a prevalent type of action, the limited and disjointed scope of legislative actions, and, especially, the poor monitoring and control show the need for deep changes in the work process of the Senate's technical committees and, therefore, of the Senate's technical support unit.