This study investigated self-perceived work-related stress, along with salivary IgA (s-IgA), cortisol and 3-methoxy-4-hydroxyphenyl glycol (MHPG) in 38 neonatal intensive care unit (NICU) nurses and 26 general ward (GW) nurses. To adjust for sociodemographic characteristics, the two groups of nurses were strictly matched for age, gender (feminine), average work experience and marital status (unmarried). General fatigue and anxiety were significantly higher, and depressive mood tended to be higher, in NICU nurses compared to GW nurses, based on Cumulative Fatigue Symptoms Index scores (p < 0.05, p < 0.05, p = 0.079, respectively). s-IgA concentrations were also inversely correlated with self-perceived work-related stress and were significantly lower in NICU nurses than in GW nurses (p < 0.01). There tended to be a positive association between high cortisol concentrations and the CFSI subscale of depressive mood in both NICU and GW nurses (p = 0.053). Cortisol and MHPG levels were not different between NICU and GW nurses. These work-related stress markers, both self-perceived (CFSI) and biological (s-IgAand cortisol concentrations), highlight the importance of creating and sustaining healthy work environments for NICU and GW nurses. Copyright © 2011 John Wiley & Sons, Ltd.