The presence of context-specific communication sounds, structurally different call types related to particular situations and potentially expressing distinct emotions of the caller, were not systematically studied in infants of strepsirrhine primates. We exposed suckling's of gray mouse lemurs (Microcebus murinus) in an infant separation paradigm to three distinct contexts (isolation, threat-induced, grooming). An audio–videographic analysis of sound-correlated infant behaviors and a simultaneous multiparametric sound analysis revealed context-specific calls. Peak frequency predicted their acoustic classification best. Findings provided first evidence for a strepsirrhine primate that infant communication sounds may express distinct contexts and thereby infant's need reliably. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 708–718, 2007.