Cover - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2021	Jul. 16, 2021	Oct. 31, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Apr. 30, 2021
Current Fiscal Year End Date	--04-30
Document Transition Report	false
Entity File Number	001-11504
Entity Registrant Name	CHAMPIONS ONCOLOGY, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	52-1401755
Entity Address, Address Line One	One University Plaza, Suite 307
Entity Address, Postal Zip Code	07601
Entity Address, City or Town	Hackensack
Entity Address, State or Province	NJ
City Area Code	201
Local Phone Number	808-8400
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	CSBR
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
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 50.1
Entity Common Stock, Shares Outstanding (shares)		13,415,066
Documents Incorporated by Reference	Portions of the Registrant’s definitive Proxy Statement for its 2021 Annual Meeting of Shareholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended, are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000771856
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021