The effect of an environmental field trip on student learning in one middle school in the mid-Atlantic region of the United States was examined. An experimental one-group pretest-posttest group design was implemented on a sample of 579 students which comprised 12 groups. Although a t-test for dependent samples indicated that less than half of the groups showed a statistically significant improvement from pretest to posttest at the p less than 0.05 level, a group item analysis indicated that in only 1 out of 60 instances was the group mean lower than 70% on a posttest question (and in 36 out of 60 instances, the group mean was 90% or higher on a posttest question), indicating that most students were able to demonstrate learning of the material contained within the field trip immediately afterwards. Pretest and posttest items are appended. (Contains 1 table.)