Background: The use of medical cannabis (MC) in cancer symptom treatment has been increasing. Since its legalization is limited to select states, there are few clinical trials that have studied the effectiveness and safety of MC, and even fewer studies in the elderly patient population. Given this, we aimed to evaluate the effects of MC on nausea, appetite, and body mass index (BMI) of elderly cancer patients. Methods: We conducted a retrospective chart review of patients age 65 and older prescribed MC in the year 2018 in an outpatient palliative care clinic at a comprehensive cancer center. Nausea and appetite were measured by numerical rating (0-10) and BMI was recorded with data collected at consecutive clinic visits before and after MC use. Results: Eight-three patients aged 65 and over were included in our analysis. Half of patients were age 65-70, while 12% were age 76 or older. More than half were male (58%) and Caucasian (92%). For patients with anorexia or nausea, 58% had previously used cannabis. For nausea, 58% were prescribed ondansetron, 53% were prescribed prochlorperazine or metoclopramide, and 20% were prescribed olanzapine. For anorexia, 24% were prescribed mirtazapine, 6% were prescribed dronabinol, and 1% were prescribed megestrol. The majority of patients used oil (64%), with one-third using vape (33%) and fewer using pill (17%) and powder (5%). Patients primarily used high THC (50%) or equal THC:CBD (45%) formulations initially, with only 7% using high CBD products. The median nausea and anorexia trended towards improvement, though neither was significant (delta nausea = 0.1, p = 0.81) nor anorexia score (delta anorexia = 0.7, p = 0.69). BMI worsened despite MC use (delta BMI 1.9, p < 0.001). Conclusions: In this study of elderly patients with cancer prescribed MC, more than half had previously used cannabis. Two-thirds of patients with anorexia were using MC first-line for appetite stimulation. The majority of patients used oil, with vape next most commonly used, and the vast majority of patients using high THC or equal THC:CBD initially. Use of MC was not associated with a significant improvement in nausea nor anorexia, and BMI significantly decreased despite MC use.