This study examines the effects of daily primary objective stressors (behavioral problems exhibited by persons with mild cognitive impairment) and subjective stressors (unpleasant marital interactions) on the diurnal cortisol pattern and the diurnal pattern of salivary alpha-amylase (sAA) of spousal care partners. Thirty spouse care partners (age 59-85 years) participated in a 7-day diary study and submitted saliva samples on 4 consecutive study days, totaling 406 valid samples. Results from multilevel models revealed that daily objective stressors were associated with elevated cortisol levels and a flatter slope but were not associated with sAA activity. Conversely, unpleasant marital interactions were associated with flatter sAA slopes but not associated with cortisol activity. Furthermore, daily levels of sAA moderated variations in cortisol in the presence of a primary objective stressor. The utility of our research has implications for advancing scientific understanding of biosocial processes and the development of stress prevention and intervention strategies.