Improving solid waste management practices and policies in developing countries requires handling of difficult topics such as littering. In this work we investigated littering in Jordan, a developing countries. A questionnaire was constructed to solicit people’s justification for littering. The questionnaire considered three categories: social reasons, physical reasons, and psychological reasons. In addition, the study considered the socio-demographic characteristics of the respondents. People’s view of the norm in Jordan, their education, and the belief that litter cleaning is not their job were the most significant reasons in the social category for littering. Infrastructure and honoring bread were the most significant reasons in the physical reasons for littering. Disgust and fear of sickness were the most significant reasons among the psychological reasons for littering. Results of the socio-demographical characteristics study indicate that young people and people aged 50 years and above tend to litter more, minimum education and basic environmental awareness are crucial in improving people’s littering behavior, littering is not related to income, and there are no gender differences in littering for psychological reasons.