OBJECTIVE: To determine the degree of compliance with Transport Canada’s Transportation of Dangerous Goods Regulations for transporting infectious substances in Canada.DESIGN: A three‐phase study including observation of packages arriving at the British Columbia Centre for Disease Control (BCCDC) provincial laboratory; observation of requested samples of either an Escherichia coli culture or serum, not human immunodeficiency virus (HIV) or HbsAg positive, from laboratories; and a questionnaire concerning training and certification of packers in laboratories.RESULTS: During phase 1, 500 packages arriving at the BCCDC provincial laboratory were assessed. All arrived intact, with 384 (76.8%) in a firm outer package. Only 178 (35.6%) contained absorbent material. Six samples were known to contain human immunodefiency virus or hepatitis B; all were appropriately packaged. Of the remainder, 11 (2.2%) were considered overpackaged, 192 (38.4%) acceptably packaged and 191 (38.2%) inadequately packaged. In phase 2, 138 requested packages were assessed. All arrived intact, 132 (95.7%) in a firm outer package. Ninety‐six (69.6%) contained absorbent material. Only six (4.3%) were considered inadequately packaged. In phase 3, 171 laboratories responded to a questionnaire. Fifty‐nine were from small laboratories, 53 from intermediate laboratories and 23 from large laboratories. Most laboratories (55.4%) relied on in‐house resources to train packers. Only 26 (15.3%) facilities had no certified packers, and 60.8% noted they had a formal copy of the regulations available in the laboratory. Laboratory characteristics associated with the likelihood of overpackaging included number of technologists (χ2=5.72; P=0.058), number of samples processed by laboratories (χ2=8.46; P=0.015) and being a private laboratory as opposed to being a hospital laboratory (Fisher Exact two‐tailed 0.040).CONCLUSIONS: Canadian laboratories tend to package safely and within the acceptable range of regulation, although not within the precision of regulation. Most laboratories have trained and certified packers. The most common error is the use of outer packaging that is not firm. Larger laboratories tend to overpackage resulting in increased costs.