In the new Masoala exhibit of the Zurich Zoo four self-operated food boxes were installed to encourage arboreal behavior and higher activity levels, and to increase the attractiveness to visitors of a group of three white-fronted lemurs (Eulemur fulvus albifrons) and one Alaotran gentle lemur (Hapalemur griseus alaotrensis). Data obtained by direct observations with and without food boxes present were compared. In addition, visitors were surveyed to investigate attractiveness of the lemurs. Overall activity and locomotor behavior increased due to food box presentation. Furthermore, the visitor survey documented that the lemurs were spotted more often in trees when the food boxes were present. Because behavior patterns of the subjects approached natural levels with food boxes, the presentation of self-operated food boxes seems a valuable tool to improve the captive environment of lemurs. Zoo Biol 0:1–10, 2005. © 2005 Wiley-Liss, Inc.