Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 04, 2021	Jun. 30, 2020
Document and Entity Information
Entity Registrant Name	CATABASIS PHARMACEUTICALS INC
Document Type	10-K/A
Document Period End Date	Dec. 31, 2020
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	CATB
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		23,417,006
Entity Public Float			$ 101,269,279
Entity Central Index Key	0001454789
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false