Factual error: Season 4 Episode 16 "Trio": When Sam breaks her leg, Dr. Keller discusses with McKay the possibility of internal bleeding, then returns to splint her leg and offer her some ibuprofen for pain. A doctor concerned about internal bleeding would never offer a patient ibuprofen, as it inhibits blood clotting.

Other: In the third season, episode "Phantoms", the crew members are in a forest having hallucinations because of the wraith machine. Sheppard is hallucinating that he is in the desert during the war helping an injured soldier, so when he's walking around why isn't he bumping into trees? He sees nothing but sand, even mentions it at one point, but they are in the forest and he walks around pretty freely.

Factual error: Anytime a character fires a missile at an airborne target, it's invariably from an M136 antitank launcher. The M136 is designed to hit relatively slow moving ground vehicles and is useless against fast moving airborne targets. (This is because used M136 tubes can't be reloaded and are very cheap to use as props).

Plot hole: In early episodes, when Sheppard and his team are attempting to capture a Wraith, they ambush him and his soldiers with tasers. The taser just irritates the Wraith. Why don't they have Zat guns? (The real reason, of course, is that Wraith stunners will be introduced in 2 or 3 episodes.) But it makes no sense to not bring such a useful non-lethal weapon along into unknown territory.

Continuity: In the second season, episode "Condemned", in the beginning when the crew is in the jumper, Ronan Dex has his hair tied back. When they land on the island and walk into the camp, his hair is down, and then they have to run back to the jumper when the prisoners start shooting at them. When they get back in the jumper, Ronan's hair is tied up again.

Plot hole: Why do Dr. Beckett and Dr. Keller use so much Earth medicine? The Go'auld and Asgard both have devices for nearly instant healing and the Ancients are far more advanced than either of them. While they might be reluctant to use sophisticated machines to perform surgery or treat disease, things like cuts, bruises and broken bones should be easily fixed. And we know such machines exist, the Go'auld developed their sarcophagi on just such a device.