To describe and quantify independent prescribing of oncology pharmacists working in adult, ambulatory cancer centers in Alberta, Canada. A retrospective chart review of oncology pharmacists prescribing in the electronic health record, ARIA® was conducted. Prescriptions from January 1, 2018 to June 30, 2018 were analyzed. Descriptive statistics were used to quantify prescription volume and class of medications prescribed. A cross-sectional analysis was then performed on a random sample to determine the type of prescription intervention and evaluate pharmacist documentation. Over 6 months, 3474 prescriptions were ordered by 33 clinically deployed pharmacists. The median number of medications prescribed was 7 per month (interquartile range: 1.50-27.00; Range: 0.17-79.5). When prescribing was standardized by pharmacist's time clinically deployed, the median was 21.67 (interquartile range: 5.00-79.67; range: 0.67-216.67) prescriptions per month per full-time equivalent. The most prescribed class of medication was antiemetic (24.1%). From a sample of 346 prescriptions, 172 (50%) were new medications initiated, 160 (46%) were the continuation of existing prescriptions and 14 (4%) were prescription dosage adjustments. Adherence to the specified documentation standards was 47%. Oncology pharmacists utilize their independent prescribing to initiate and continue supportive care medications for cancer patients. The prescribing volume varied greatly among pharmacists. Opportunities exist to further engage pharmacist prescribing.