Prior studies have documented the domestic dog's (Canis lupus familiaris) sensitivity to human attentional state, including a tendency to preferentially beg for food from attentive individuals and an ability to selectively perform forbidden behaviors when humans are not looking. Due to the success of dogs on perspective-taking tasks, some have hypothesized that domestic dogs may have theory of mind, or the ability to infer what other individuals know. Here we provide the first evidence that nondomesticated canids, grey wolves (Canis lupus), are also sensitive to human attentional state under some conditions. We also demonstrate that dogs do not display an undifferentiated sensitivity to all visual cues of attentional state. Rather, dogs are more sensitive to stimuli encountered in their home environment. Some dogs perform poorly on perspective-taking tasks. These findings have important implications for the interpretation of research designed to understand complex social cognition across species.