Document and Entity Information - shares	3 Months Ended
	Dec. 31, 2019	Feb. 03, 2020
Document and Entity Information [Abstract]
Entity Registrant Name	APPLIED DNA SCIENCES INC
Entity Central Index Key	0000744452
Trading Symbol	APDN
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--09-30
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		3,485,399
Document Type	10-Q
Document Period End Date	Dec. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false