Trekking to high-altitude locations presents inherent health-related hazards, many of which can managed with specific first aid (FA) training. This study evaluates the trip preparation, FA knowledge, and FA self-assessment of trekkers (organized by tour operators vs. individually planned tours). Data obtained shall be used for specific FA trip preparation and management of emergencies en route for this population. A total of 366 trekkers on the Everest Base Camp Trek, Nepal, were interviewed using a questionnaire specifically designed to evaluate their FA knowledge and management of emergencies. Data evaluation was performed using descriptive statistics. A total of 40.5% of trekkers experienced at least one medical incident during their trip, of which almost 50% were due to acute mountain sickness (AMS). There was more AMS in commercially organized groups than in individually planned ones (55% vs. 40%). For more than 50%, no medical care was available during their trip. A total of 80% could answer only 3/21 FA questions completely correctly. Only 1% showed adequate knowledge concerning FA strategies. A total of 70% were willing to enroll in an FA class specialized towards the needs of trekkers. The importance of high-altitude FA knowledge and trip preparation is widely underestimated. There is an unmet demand amongst trekkers for specific wilderness FA classes.