Objective: The objective of this study was to investigate the effect of relaxation techniques on the stress/anxiety of parents with hospitalised premature infants, three months following discharge from the neonatal intensive care unit. Study design: A randomised controlled trial was conducted in the neonatal intensive care unit of a tertiary maternity hospital including 59 parents, who were randomised into two groups: 31 in the intervention group and 28 in the control group. Parents in the intervention group practiced three different relaxation techniques, in addition to undergoing the same information-based training courses as did the parents of the control group. Data collection: Data were collected 10-15 days post delivery and three months post discharge. The assessment measures included the Perceived Stress Scale, the State and Trait Anxiety Inventory 1 and 2 and salivary cortisol levels. Results: The psychometric assessment at baseline was comparable between the two groups. The intervention group showed a significant reduction in trait anxiety (p = 0.02) compared with the control group three months post discharge. The perceived stress decreased in both groups (p = 0.699). No difference in salivary cortisol levels was detected. The multivariate analysis revealed that higher initial stress levels (p < 0.001) and university/college education (p = 0.003) were associated with higher parental stress, whereas moderate-to-high income satisfaction was associated with lower parental stress (p = 0.003). Conclusion: Further long-term follow-up of families with a neonatal intensive care unit experience could assess more delayed effects of stress management by relaxation techniques. (C) 2015 Elsevier Ltd. All rights reserved.