Background: Prior researchers developed an instrument to measure perceived design thinking ability of first-year students interested in engineering, and they validated the instrument through exploratory factor analysis. Purpose/Hypothesis: Our study uses the previously developed instrument to evaluate perceived design thinking ability of senior engineering students. We make a cross-sectional comparison of this measure on a national scale. Design/Method: We surveyed a national sample of senior engineering students in 2018 and conducted a cross-sectional comparison with results from a 2012 national sample of first-year students who were interested in declaring an engineering major. Two-way analysis of variance tests compared average design thinking scores across sample groups. Confirmatory factor analysis was conducted to improve the design thinking instrument. Results: First-year students who intended to declare an engineering major score significantly higher (2.80) on the design thinking scale than senior engineering students (2.59) with a medium effect size of 0.4. The senior engineering sample performs significantly worse on the feedback seeking and experimentalism instrument items, but significantly better on the integrative thinking and collaboration items. We found no significant differences in perceived design thinking ability among engineering disciplines among senior students. Conclusions: Feedback seeking and experimentalism are traits that engineering educators should develop in their students to improve perceived design thinking ability. Incorporation of user-centered design and divergent thinking in the engineering classroom are recommended as avenues to foster feedback seeking and experimentalism. We also offer recommendations to improve the design thinking instrument for future research.