Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	APPLIED DNA SCIENCES INC
Entity Central Index Key	0000744452
Trading Symbol	apdn
Current Fiscal Year End Date	--09-30
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		37,885,157
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Small Business	true
Entity Emerging Growth Company	false