Although rooted in reality, partner perceptions often reflect wishful thinking due to perceivers’ needs. Dispositional needs, or motives, can differ between persons; however, little is known about their differential associations with everyday partner perception. The present study used data from a 4–week experience sampling study (N = up to 60942 surveys from 510 individuals nested in 259 couples) to examine the effects of perceivers’ partner–related implicit and explicit communal motives on the perception of (i) global communal partner behaviour and (ii) specific communal and uncommunal partner behaviours. The results of truth and bias models of judgement and quasi–signal detection analyses indicate that strong implicit communal approach motives and strong explicit communal motives are associated with the tendency to overestimate the partner's communal behaviour. Additionally, strong implicit communal approach motives were associated with the tendency to avoid perceptions of uncommunal partner behaviour. Neither implicit nor explicit communal motives had an effect on accuracy in the perception of particularly communal partner behaviour. The results highlight the relevance of both implicit and explicit communal motives for momentary partner perceptions and emphasise the benefits of dyadic microlongitudinal designs for a better understanding of the mechanisms through which individual differences manifest in couples’ everyday lives. © 2019 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology