This study examined the development of caregiver mind-mindedness--defined as the propensity to see one's child as an agent with an independent mind--across the first 1,000 days of life. At four timepoints (i.e., third trimester of pregnancy, 4, 14, and 24 months postpartum), 384 first-time mothers (M[subscript age] = 32.55, SD = 3.63 years) and fathers (M[subscript age] = 33.96, SD = 4.40 years) gave 5-minute speech samples about their infant that were coded for mind-mindedness (Meins & Fernyhough, 2015). Reflecting the local population, the 192 heterosexual couples were highly educated (84.6% of mothers, 77.1% of fathers had a degree) and ethnically homogenous (92.7% of mothers, 94.8% of fathers identified as White British). Results showed significant variability in mind mindedness within both expectant mothers and expectant fathers, with no mean group difference. Auto-regressive models demonstrated modest positive associations between prenatal and postnatal mind-mindedness. Latent change score models showed gains in mean mind-mindedness over time that, on average, were stronger for mothers than for fathers. For fathers, gains in mind-mindedness were positively associated with having an infant daughter and infant surgency. For mothers, higher socioeconomic status and more equal childcare were associated with greater gains in mind-mindedness across toddlerhood. Within-couple associations were evident for changes in mind-mindedness, but not for initial (prenatal) scores. We apply the relational account of mind-mindedness to frame our discussion of these findings that, by highlighting both developmental stability and change in mind-mindedness, suggest fruitful avenues for future research.