One hundred and fifty-four incidents of food poisoning were associated with post-process leakage (PPL) between 1921 and 1979. These occurred mainly in Great Britian (72.7%) and Canada (17.5%) from products exported from South America, Europe, Africa and Australia. Defects leading to leakage were identified as defective seams and perforations during processing; temporary microleaks during cooling; and case-cutter damage, punctures, corrosion and dents after processing. Organisms associated with the incidents were Staphylococcus aureus (100, 64.9%), Salmonella typhi (6, 3.9%), other Salmonella spp . (9, 5.8%), Clostridium botulinum (3, 2.0%), Clostridium perfringens (3, 2.0%), others and undetermined 33 (21.4%). Canned meat, fish and vegetable products were involved. In particular, corned beef contaminated with Staphylococcus or Salmonella caused 53 incidents; pork and ham products contaminated with the same organisms caused 16 incidents. Where information was available, it was found that the median amount of meat contaminated with Salmonella consumed by ill persons was 105 g. For Salmonella -contaminated fish the amount associated with illness was between 40 and 320 g. Although many of the PPL incidents recorded occurred decades ago, significant outbreaks from this cause have appeared in the last few years. Appropriate action should be taken to reduce PPL at the manufacturing and retail level.