Given recent evidence that contact with nature can enhance cognitive processes, we measured whether students who took a brief on-campus walk in a natural environment showed improved retention of learned materials. Using a within-subjects design, we compared the effects of 10-minute walks in nature, urban, and indoor environments on long-term memory for word lists. Recall and recognition for word lists were tested in the indoor environment either after each walk (Experiment 1) or before each walk (Experiment 2). We failed to find an influence of walk type on either memory test in either experiment. Thus, contact with nature did not enhance students' long-term memory under the conditions we tested. Our results contrast with a recent study in which learners showed better memory for lecture materials learned in a nature-enhanced classroom than in a control classroom. We identify potential explanations for our null findings and suggest future research directions. Key Words: Nature - Environment - Memory - Recall - Recognition.