Taming a beast can be made easier with some preparation. Some of the beasts you encounter have special attacks which will cause your attempt to tame them to fail.
You cannot have another pet active if you want to tame a new one. Stable or dismiss any pet you have active before attempting to tame a new one.
Interruptions will fail the attempt. This includes stuns, knock downs, and silence, but does not include the daze effect.
You can only tame beasts that are at your level and below. Raid bosses count as the level the raid was designed for, plus 3. For example, the quilen of the Stone Guard require at least level 93 to tame.
Some beasts cannot be tamed. Only certain families of beasts are tamable, and even within those families not every member is tamable. To ensure the beast you want is tamable, you may want to cast [Beast Lore] on it for more information.
Having a bodyguard follower will break the taming process, so it's better to dismiss the bodyguard beforehand.
Patch 7.1.0 (2016-10-25): Now learned at level 13 (was 10).
Patch 7.0.3 (2016-07-19): Now takes 6 seconds, down from 10.
Patch 4.3.0 (2011-11-29): The casting bar for Tame Beast should now always indicate the correct cast duration at high values of haste.
Patch 4.1.0 (2011-04-26): Now tames pets to match the hunter's level, rather than 3 levels below.
Patch 4.0.1 (2010-10-12): No longer reduces armor while taming. Time taken to tame pet reduced by 10 sec.
Patch 0.11 (2004-09-29): No longer requires the Hunter or the target beast to be out of combat.
Patch 0.10 (2004-09-18):Beast Taming is now renamed to Tame Beast