Tourism accounts for a substantial and increasing portion of the Sub-Saharan African economy. In Tanzania, the number of international tourist arrivals nearly doubled from 2010 to 2018, and many of them participated in nature-based tourism. In addition to the jobs and revenue created by tourism, it has both positive and negative impacts on a place's environment. For example, it can fund conservation efforts, but it can also lead to deforestation from infrastructure development. This paper focuses on the environmental perceptions of tourists who traveled to Tanzania and tour operators working in the country. Environmental perception assesses an individual's ability to recognize how they truly view and react to their environment. This study builds on the existing literature on tourist perceptions to compare three aspects of perceptions. First, it compares tourist perceptions of their personal environmental impact to the impacts of other tourists. Second, it compares tourist perceptions of their personal impacts to the perceptions of tour operators. Third, it compares how tourists perceive their behaviors at home to their behaviors while traveling. Using results from online surveys of 47 tourists and 16 tour operators, this study found that tourists attribute negative environmental impacts to others and positive impacts to themselves. It found similar gaps between tourist and tour operator perceptions, with tourists both over and underestimating their impacts compared to operator perceptions. It found that tourists are more proactive at minimizing their environmental impacts at home than away.