The eighth edition of the magazine includes detailed advice from radical cleric Anwar al-Awlaki on attacking Western countries, including through the use of biological and chemical weapons in population centers, CNN reported.
Awlaki and the man widely believed to have been Inspire's editor, former North Carolina blogger Samir Khan, were killed in the drone attack in Yemen in September.
"The use of poisons of chemical and biological weapons against population centers is allowed and strongly recommended due to the effect on the enemy," Awlaki wrote.
He cited religious scholars he said justified such attacks.
CNN said there's no evidence al-Qaida has developed chemical or biological weapons capability.
Awlaki wrote women and children should not be deliberately attacked but if they're among '"combatants," it is "allowed for Muslims to attack them."
He said, "Muslims are allowed to target the populations of countries that are at war with Muslims by bombings or firearms attacks or other forms of attacks that inevitably lead to the deaths of non-combatants."
The magazine also includes advice on building a remote detonation device using a motorbike alarm and washing machine timer.
The ninth edition urges followers to set wildfires in the United States and includes instructions on creating an "ember bomb."
In an editorial, the magazine said, "To the disappointment of our enemies ... we are still publishing America's worst nightmare."