Abstract In recent years, new efficient experimental techniques, especially in the area of DNA sequencing, have led to a tremendous growth in available biological data. Many large sequence databases are already publicly available on the internet, and information is added at a spectacular rate. The extensive human genome project is only one of the many sources of this information. It is widely recognized that the mere gathering of data is not sufficient and that its biological interpretation is of the utmost importance. Unfortunately, the development of methods for in-terpreting the data is not keeping up with the tempo with which the data is accumulated. It is clear that many types of questions can only be asked by a computational analysis, and computer science has become an integral part of the research involving biological sequences (of DNA, RNA, or proteins). The research area combining biology and computer science is known as bioinformatics. Conventional computer methods and algorithms have been applied quite successfully in this area, but the often enormous amounts of data to be analyzed and the complexity of biological systems leave many interesting problems beyond the reach of conventional approaches. The challenging computational problems of bioinformatics provide interesting opportunities for applying methods from the field of artificial intelligence. In this paper, the emphasis is on discussing how methods from the field of uncertainty in AI can be relevant for some challenging problems of bioinformatics. Some necessary background information on molecular genetics in general and the human genome project in particular is provided at the beginning of the paper.