The past two decades have witnessed a dramatic shift in how science is taught. Electronic portfolios—hereafter referred to as e-portfolios—represent one possible way to bring assessment into alignment with technology-based instruction. In this chapter the author briefly describes what characterizes an e-portfolio and how it can be used for assessment in college-level science courses. Guidelines for instructors are provided to help students develop e-portfolios, along with a simple grading rubric for evaluating them. Finally, the author presents data from student reflections and course evaluations that speak to how students value e-portfolios in science courses.