The geography subject in Swedish upper secondary school is in a marginalized position with just two national programs having it as a mandatory subject. No mention of the skill of spatial thinking is made in the regulation documents from the Swedish National Agency for Education. To investigate the spatial thinking in the Swedish upper secondary school, I constructed a test that 140 students conducted. From the results it was possible to deduct that the students performed well in areas of spatial thinking that deals with geographical features like points, lines and polygons, but not so well when faced with tasks concerning several spatial facts, overlay, and mentally visualizing 3-D images from 2-D information. Males generally scored higher than females in the test, especially if only answers that the students felt confident of were counted. Students from the Natural Science Programme outperformed the students from the Social Science Programme, even though the former didn’t have any formal education in geography from the upper secondary school. The thesis argues that a larger focus on spatial thinking in the geography subject could benefit the development of both a stronger stance for the subject in the education system, and the abilities and knowledge tied to spatial thinking of the students, especially those that are lacking formal education in other subjects that train the spatial thinking, mostly mathematics and physics.