Background: Only a handful of longitudinal studies have explored the effects of both parents in early parenthood on children's cognitive development, and no study has controlled for simultaneous early childhood education and care (ECEC) experiences. Aims: To examine the similarity of each parent's cognitive guidance and contribution to children's pre-mathematical outcomes across parent gender while controlling for amount of ECEC. Sample: A longitudinal study on 66 Finnish two-parent families and their children. Methods: Both parents' autonomy support and scaffolding behaviour were observed during play interactions with the child at 2;0. Children's numerical and spatial skills were tested at 3;0 and 4;0. Parental reports on amount of ECEC in months were collected at 2;0, 3;0, and 4;0. Results: The two parenting constructs were conceptually similar across parent gender as demonstrated by fairly strong measurement equivalence. While mothers on average showed more scaffolding and equal amounts of autonomy support compared to fathers during play interaction, they displayed less variability in the former and more variability in the latter behaviour. The contribution of mothers' and fathers' cognitive guidance was more similar for children's numerical than spatial development. Both parents' education positively predicted autonomy support but not amount of ECEC exposure, which was positively related to numerical development. As expected, parents' education did not predict ECEC exposure, and child gender was not related to child outcomes. Conclusions: The findings are discussed in relation to measurement invariance and gender-neutral parenting in the context of early childhood.