Nest‐site characteristics can have a strong impact on reproductive success in birds. Nest sites should simultaneously protect from predators, offer shelter and provide a favourable microclimate. We studied the relationship between three agents of natural selection (predators [i.e. Adders and birds/mammals], snowfall and microclimate), nest‐site characteristics and reproductive success to determine whether these influenced preference for specific nest‐site characteristics in the Water Pipit Anthus spinoletta. Pooled over all nests, the relative importance as agents of natural selection decreased from mammalian/avian predation (15% of all nests) through Adder predation (12%) to snowfall (7%), but there were clear differences in space and time. Predation by Adders selected for nest sites surrounded by few medium‐sized shrubs. Selection by mammalian and avian predators favoured no specific nest‐site characteristics. Protection from snowfall was best in nests surrounded by relatively few medium‐sized shrubs. Microclimate had a strong influence on nestling survival and duration of nestling period. In nests on ENE‐facing slopes, where maximum temperatures were reached in the morning, nestling survival was higher than on WSW‐facing slopes, where temperature maxima occurred in the afternoon. Our results indicate that weak, but significant, directional selection is acting on preference for certain nest‐site characteristics through effects on survival and development of nestlings. As predation and snowfall are unpredictable, the evolution of an optimal nest placement strategy is unlikely on a small scale. On a larger scale, however, choice of one breeding area over another may be favoured because of predictable differences between locations in terms of survival and nestling development.