Purpose: The purpose of this study was to assess particular student outcomes when design thinking was integrated into an environmental engineering course. The literature is increasingly promoting design thinking for addressing societal and environmental sustainability engineering challenges. Design thinking is a human-centered approach that identifies needs upfront. Design/methodology/approach: In an undergraduate engineering course, Design for the Environment, students have begun to obtain hands-on experience in applying design thinking to sustainability challenges. This case study investigates the association between the use of design thinking and student creativity with sustainability design solutions. Student perspectives on their own creativity and future sustainable design practices as a result of the course were also investigated. Findings: The findings were favorable for design thinking, being associated with a significant difference and medium-to-large effect with regards to solution novelty. A qualitative analysis showed a positive association between design thinking and students' perceptions of their creativity and future anticipated sustainability practices. Using a content analysis of reflective writings, students' application of design thinking was assessed for comprehensiveness and correctness. A two-week introductory design-thinking module and significant use of in-class active learning were the course elements that most notably impacted students' use of design thinking. Practical implications: This case study preliminarily demonstrates that application of design thinking within an environmental engineering course may be associated with beneficial outcomes related to creativity and sustainability. Originality/value: A review of the literature did not uncover studies of the use of design thinking for undergraduate socio-environmental challenges to promote creativity and sustainable-practices outcomes, although the literature has been calling for the marrying of these two areas.