This article focuses on preterm infants' early triangular capacity, restricted to the use of triangular bids in interaction with their parents. An observational setting, the Lausanne Trilogue Play (LTP), is used for studying the patterns of interaction. This is an approach focusing on the family as a whole. These observations are part of a study consisting of video observations and interviews with the parents when the preterm infants are three and nine months, adjusted age. In this study, two out of nine infants were found to actively use triangular bids in interaction with their parents at three months, adjusted age. These two cases are presented to illustrate and discuss preterm infant's early use of triangular bids.