This study investigated the impact of virtual guest speakers facilitating asynchronous discussions. The setting was an online instructional technology course with 16 graduate students and two guest speakers. The research reports the quantity and level of critical thinking of the students and guests. Each posting was coded for frequency and critical thinking. The results indicate that higher-order thinking occurred and student participation remained high throughout the length of both threaded discussions, regardless of the amount of postings and time spent by the guests. The findings support that guest speakers can be used sparingly in online discussions while still maintaining the quality of the online discussion and frequent, meaningful interactions among students.