Food science laboratory courses are traditionally taught as a series of preplanned laboratories with known endpoints. In contrast, inquiry-guided (IG) laboratories allow students to ask questions, think through problems, design experiments, then adapt and learn in response to unexpected results. This study examined the effects of converting the course, "Analytical Techniques in Food and Bioprocessing Sciences" from a traditional approach (2008 to 2010 data) to an IG approach (2011 data) by assigning teams of 2-3 students a food and a set of 5 analyses to conduct over the course of the semester. Students were required to choose and justify the use of specific methods for each analysis, as well as to develop a supply list and a budget for the semester-long project. During the semester, students were required to post and discuss their weekly progress with the instructor, teaching assistants, and the rest of the class using an online discussion forum. At the end of the semester, students were required to present the results of their analysis in both oral and written formats. Overall course grades were significantly higher (P less than or equal to 0.05) using IG in 2011 compared to 2010 and 2009, but not to 2008 grades. Numerical course evaluations for the instructor, overall course, and lab, as well as written course evaluations all significantly (P less than or equal to 0.05) improved. This suggests that an IG approach may measurably improve student performance in terms of course grades and the ability to complete semester long projects. It may also increase student satisfaction with the course, as measured by numerical and written end of semester surveys. (Contains 4 tables and 1 figure.)