Three new records of the highest treelines in the northern hemisphere are presented here, based on the definition of a “tree.” The tree species with the highest treeline in the northern hemisphere is Juniperus tibetica Kom. The highest forest stand is located at 4,900 m in southeast Tibet. The highest tree stands of Juniperus indica Bertol. in the Himalaya were found in northern Bhutan at 4,750 m. Information from such observations is decisive for the development of hypotheses on the limits of tree growth. The authors compare the present findings with findings on highest treelines in other mountain areas worldwide and draw some conclusions.