R v Smith (Thomas Joseph) [1959] 2 QB 35 is an English criminal law case, dealing with causation and homicide.

The court ruled that neither negligence of medical staff, nor being dropped on the way from a stretcher twice, constituted breaks in the chain of causation in murder cases.

On the way to the medical centre, C had been dropped twice by comrades carrying him and, on arrival, the doctor failed to notice that one of C's lungs had been pierced, causing haemorrhage, and the treatment provided was, as it later turned out, inappropriate and harmful.

"[1] The jury agreed with one of the competing propositions put to it, namely that the stabbing was still the "operating" (interpreted as primary or main) cause of death, and therefore found guilt.

The case has been cited with approval and stated as applied to date, such as in the 2017 Northern Irish appeal, R v Okrasa.