We report in the present study the occurrence of contracting defensive behaviour in three treefrogs of the genus Phyllomedusa: P. azurea, P. iheringii and P. tetraploidea. It consisted of limbs bent close to the body, dorsum arched with the head towards the belly, and eyes partially closed. This behaviour was previously unreported for P. iheringii and P. tetraploidea and it seems to be a passive defensive strategy against snakes or other predators, characteristic of phyllomedusine frogs. Fil: Borteiro, Claudio. Museo Nacional de Historia Natural, Montevideo; Uruguay Fil: Baldo, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina Fil: Kunz, Tobias Saraiva. Universidade Federal do Rio Grande do Sul; Brasil Fil: Perez, Renata. Universidade Federal do Rio Grande do Sul; Brasil Fil: Petry Eltz, Rodrigo. Universidade Federal do Rio Grande do Sul; Brasil Fil: Kolenc, Francisco. Museo Nacional de Historia Natural, Montevideo; Uruguay