Introduction: As individuals age, there is an increased focus on social relationships (Carstensen, 2006). However, age-related changes in the brain can interfere with social functioning (Ebner, et al, 2012; Mather, et al, 2005; Ruffman, et al, 2008). While age-related changes in cognition are well studied, social-cognitive changes in aging are still underinvestigated, especially the brain mechanisms underlying this phenomenon. The administration of intranasal oxytocin (OT) has the potential to modulate social cognition (De Dreu, 2014) by altering BOLD signal in regions of the social brain (eg. amygdala and vmPFC) (Ebner, et al, 2016). Currently, there is very little known about the role of OT in human development in aging (Campbell, et al, 2014; Huffmeijer, et al, 2012). Methods: 40 young (18–31 years, 50% female) and 39 older (63–81 years, 59% female) were randomly assigned (in a double-blind design) to self-administer either 24 UIs of intranasal OT or placebo (P) 70-90 minutes prior to resting-state fMRI. T1-weighted anatomical reference images, using an MP-RAGE sequence (sagittal plane, FOV = 240 mm × 240 mm × 170; 1 × 1 × 1 mm isotropic voxels), and functional gradient-echo-planar imaging (EPI) data, during an open-eye, white cross-hair on black background, 8 minute resting-state scan (38 interleaved slices, TR 2 sec, TE 30 msec, FOV 252 × 252 × 133 mm, 80 × 80 × 38 mm matrix, flip angle 90°, in plane resolution of 3.15 × 3.15 mm, slice thickness 3.5 mm, 0 mm skip), were acquired with a 3T Philips Achieva MR Scanner using a 32-channel head coil. Preprocessing, including slice time correction, motion correction with artifact rejection, spatial normalization, and smoothing with an 8 mm Gaussian kernel, were implemented with Functional Connectivity Toolbox (Whitfield-Gabrieli, et al, 2012; http://www.nitrc.org/projects/conn/). Results: Younger individuals showed significantly greater overall anterior cingulate (AC) activity in P condition (p=.044). Intranasal OT administration significantly increased activity in the AC in both younger and older women (p=.024), but not men, when compared to P. The effect was slightly greater in older women than younger, but this effect was not significant potentially due to sample size.There were no significant gender effects in AC activity during rest between males and females in either younger or older P control groups. Conclusions: Intranasal OT has differential gender effects on AC activity during resting-state, increasing activity in women but not men. Additionally, there is evidence for age differences in overall AC activity at rest.