University students report high levels of stress. Although causal work is limited, one popular approach to promote stress relief is animal visitation programs (AVPs). We conducted a randomized trial (N = 249) examining effects of a 10-minute AVP on students' salivary cortisol levels. Undergraduate students were randomly assigned to one of four conditions: hands-on AVP (petting cats and dogs; n = 73), AVP observation (watching others pet animals; n = 62), AVP slideshow (viewing images of same animals; n = 57), or AVP waitlist (n = 57). Participants collected salivary cortisol upon waking, and two samples were collected 15 and 25 minutes after the 10-minute condition, reflecting cortisol levels at the beginning and end of the intervention. Controlling for students' basal cortisol, time awake, and circadian pattern, students in the hands-on condition had lower posttest cortisol compared to slideshow ([beta] = 0.150, p = 0.046), waitlist ([beta] = 0.152, p = 0.033), and observation ([beta] = 0.164, p = 0.040). A 10-minute college-based AVP providing hands-on petting of cats and dogs provides momentary stress relief.