Self-reports of mothers currently breast-feeding (n = 561) and mothers who had breast-fed in the past (n = 452) were compared for perceived stress, self-reports of upper respiratory infection symptoms, and physician visits for psychological illnesses. Possible demographic confounds were controlled statistically. In analyses examining breast-feeding status as a dichotomous variable (current vs. past), breast-feeding was negatively associated with perceived stress and upper respiratory symptoms (the latter association dissolved when controlling for perceived stress), but not with physician visits for psychological illnesses. However, analyses of the continuous variables of frequency of breast-feeding and cumulative amount of breast-feeding revealed negative associations, and analyses of times since last nursing revealed positive associations with likelihood for physician visits for psychological illnesses. Frequency of bottle-feeding was positively associated with perceived stress. The results support the interrelatedness of breast-feeding and maternal health in online mothers.