CONTEXT: It is challenging to provide supportive intensive care to infants in the neonatal intensive care unit (NICU), giving them every chance for survival, while also trying to minimize suffering for both the infant and parents. Parents who believe their infant is suffering may alter treatment goals based on their perceptions; however, it is unknown how parents come to believe that their infant may be suffering. OBJECTIVES: To examine bereaved parents' perceptions of infant suffering in the NICU. METHODS: Parents completed a qualitative interview exploring their perceptions of the level of suffering that their infant experienced at the end of life. Parents whose infant died in a large Midwestern Level IV regional referral NICU from July 2009 to July 2014 were invited to participate. Thirty mothers and 16 fathers from 31 families (31 of 249) participated in telephone interviews between three months and five years after their infant's death. RESULTS: Four themes emerged from the qualitative analysis: 1) the presence/absence of suffering, 2) indicators of suffering, 3) temporal components of suffering (trajectory), and 4) influence of perceived suffering on parents, infants, and clinical decision making. CONCLUSION: Parents used signs exhibited by infants, as well as information they received from the health care team to form their perceptions of suffering. Perceived suffering followed different trajectories and influenced the decisions that parents made for their infant. Soliciting parent perspectives may lead to improvements in the understanding of infant well-being, particularly suffering, as well as how parents rely on these perceptions to make treatment decisions for their infant.