Typhoid fever and dengue hemorrhagic fever are common diseases in Indonesia. Typhoid fever is caused by bacteria while dengue hemorrhagic fever is caused by the dengue virus. Both of these diseases are often misdiagnosed because they have the same symptoms as other diseases so that they can cause the high rate of death. Therefore, it takes an expert system as a tool to diagnose typhoid fever and dengue hemorrhagic fever to be handled quickly and precisely. The Expert system built by using the Sugeno Fuzzy Logic method. It expected to be a solution to facilitate the public to diagnose typhoid fever and dengue hemorrhagic fever based on the symptoms and get treatment solutions. This study has produced expert system to diagnose typhoid fever and dengue hemorrhagic Fever. It had been tested 86 cases of data with an accuracy value is 80.2%.