This study investigated HPA and vagal functioning as correlates of parenting in mothers of 175 six-month-old children. Salivary cortisol indexed HPA functioning and respiratory sinus arrhythmia (RSA) reduction indexed vagal regulation. Positive engagement and negative intrusiveness were observed during the Face-to-Face Still Face Paradigm (FFSFP) reunion and a semi-structured free play episode. Mixed modeling was used to examine differences in maternal behaviors across contexts as a function of psychophysiology. Main effects of cortisol levels, as well as interactions with RSA reduction and context, predicted negative intrusiveness. Mothers with high cortisol exhibited more negative intrusiveness if they also had lower RSA reduction. Mothers were also less negatively intrusive during the FFSFP than the free play if they had lower cortisol levels. There were no associations between psychophysiological measures and positive engagement. The findings suggest: (1) that parenting behaviors are associated with maternal stress physiology; (2) considerations of single physiological systems related to parenting behaviors may be incomplete; and (3) type and context of behaviors must be considered when examining biobehavioral associations with parenting.