Humans are social animals, but not everyone will be mindful ofothers to the same extent. Individual differences have been found,but would social mindfulness also be shaped by one’slocationintheworld? Expecting cross-national differences to exist, we examined ifand how social mindfulness differsacross countries. At little to no ma-terial cost, social mindfulness typically entails small acts of attention orkindness. Even though fairly common,such low-cost cooperation hasreceived little empirical attention. Measuring social mindfulness across31 samples from industrialized countries and regions (n=8,354), wefound considerable variation. Among selectedcountry-level variables,greater social mindfulness was moststrongly associated with countries’better general performance on environmental protection. Together,our findings contribute to the literature on prosociality by targetingthe kind of everyday cooperation that is more focused on communi-cating benevolence than on providing material benefits.