Document And Entity Information - shares	3 Months Ended
	Dec. 31, 2017	Feb. 02, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	DATAWATCH CORP
Entity Central Index Key	0000792130
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		12,352,143
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2018