Kinship (genetic relationship) recognition is known in various species and evolutionarily considered a function of inbreeding avoidance and nepotism. In humans, kinship recognition can be seen as one crucial organising component of societies. While there are a number of studies on kinship recognition based on faces, little is known about kinship recognition in voices. The present study investigated whether voices of female sibling pairs with different degrees of relatedness (monozygotic twins, dizygotic twins and non-twin siblings) are distinguishable from unrelated female individuals. Voice samples were recorded from eighteen young adult siblings (nine pairs, three per category) and each sibling’s voice was presented to 63 participants together with another voice (either from the related pair, or an age- and gender-matched sibling from another unrelated pair). Stimuli consisted of short German sentences and vowels. The listeners were asked to judge whether they heard a related or an unrelated pair, and rated their confident level for each response. Listeners’ performance to detect kinship was significantly above chance level (d’ = .467) and particularly high for monozygotic twins (d’ = .645). Furthermore, we found that kinship was recognised better with sentence stimuli compared to vowel stimuli. Overall, this study provides the first empirical evidence for human kinship recognition from voices.