In over 30 years of research Dr. Hammel-Kiesow has worked on many topics concerning the Hanse such as medieval urban history with a special focus on urban development and economic history of the medieval and early modern period. His research is to a large degree interdisciplinary with close cooperations with colleagues from the fields of archeology, building history and economic history. 

His list of publications counts approximately 150 books and essays. He is also publisher of several book series. His work was translated into many languages among them Korean and Lettish.