The report, published yesterday, says that during three evidence-gathering sessions and as part of an online consultation, "numerous" volunteers had reported verbal abuse and sexual harassment.
It says people giving evidence recounted "shocking stories of bad management, poor governance, bullying and improper behaviour" and cites intimidation and sexual harassment as examples.
"Despite the preponderance of codes of practice and guides on managing volunteers, standards remained low, especially in the voluntary sector," the report says.
"Clearly, organisations need to become better at preventing and resolving problems internally."
The report also raises the idea of a volunteer complaints commissioner or a volunteering ombudsman whose role would be to settle disputes.
"Overwhelmingly, volunteers expressed the need for an independent means of obtaining redress when things go wrong," the report says. "Deep commitment to the cause constrains volunteers from wanting to engage in whistleblowing or make external complaints."
A Volunteering England spokeswoman stressed that the organisation was not advocating the establishment of a complaints commissioner, but said it was outlining it as one possible solution.
She said the inquiry would publish more detailed recommendations in November.