This research, is there any effect of teaching the subject of environmental problems in the environment and society unit of the 11th grade high school geography course on the academic achievement of the students with the travel-observation method? It was carried out to seek an answer to the question. A quasi-experimental design with pretest-posttest control group was used in the study. The study group of the research consists of 60 students studying at a public school (Anatolian High School) in Kayseri. In the study conducted in the 2022-2023 academic year, the experimental group consisted of 30 students, 13 girls and 17 boys, while the control group consisted of 30 students, 12 girls and 18 boys. The experimental process was carried out over a period of three weeks. The quantitative data obtained as a result of the experimental procedures were analysed using SPSS 25 package programme. Frequency, percentage and arithmetic mean values were used in analysing the data; t- test and two-way Analysis of Variance for Repeated Measures on a Single Factor techniques were applied. According to the results obtained from the research, while the pre-test scores of the experimental and control group students on environmental problems were similar, significant differences were found in the post-test scores in favour of the experimental group. In the intra-group (pretest-posttest) comparison of the experimental and control groups, it was concluded that there was a significant difference in favour of the post-test scores in both groups, but when the effect size was taken into account, the increase in the experimental group was more significant. According to these results, it is recommended to encourage the use of the field trip-observation method in teaching subjects that can be understood by observation such as environmental problems.