As with any crime, a defense to Assault or Aggravated Assault can, if warranted, involve a denial of the allegations against the accused person, along with other general pre-trial and trial defenses.

However, there are three defenses that are specific to the charges of Assault and Aggravated Assault: (1) the threat was conditional (i.e. a conditional threat) (2) the threat involve words only and no action (i.e. an idle threat) (3) the alleged victim's fear was unreasonable (i.e. unreasonable fear).

A conditional threat is a threat that is conditioned on some other event occuring. For example, "come outside and I'll beat your ass" was found to be a conditional threat in LC v. State, 799 So.2d 330 (Fla. 5th DCA 2001). The court thought that this was a "conditional threat to do injury at some unspecified future time based upon a possible eventuality" and insufficient to sustain a conviction of Aggravated Battery.

An idle threat is a threat made without any "overt physical act," directed at the alleged victim, on the part of the accused person.

An alleged vicitm's fear is unreasonable if a reasonable person under similar circumstances would not believed that the defendant has an ability to carry out his threat or believe that violence is emminent.