Sarah Bidard said she was "sickened by the lack of support and empathy" for staff at Sandwell and Birmingham City hospitals after being hit with the £50 fine.
She claimed there were no parking spaces available on the staff car park and so she was left with a choice between going to work and getting a parking ticket or "driving back home".
In a blistering social media attack on her bosses, she said: "We pay our NMC (Nursing and Midwifery Council) fees. We pay our taxes.We pay our national insurance.We pay monthly parking fees.
"While I’m on shift I received this. Due to no more staff parking places. I am sickened by the lack of support and empathy you provide for your staff.
"Is this what the NHS has turned into? Either you attend your shift and get a parking ticket. Or drive back home? Well today I was charged £50 for doing my job and saving lives."
Staff are fined at the same rate as patients and visitors if they are caught flouting parking rules. If paid within 14 days, the penalty reduces to £25. New multi-storey car parks are being built at Sandwell Hospital by the trust which runs it to ease parking pressure.
Replying to the post, Sandwell and West Birmingham NHS Trust chief executive Toby Lewis reminded Ms Bidard she had the right to appeal if she felt she had been punished unfairly.
He said: "Thanks for your hard work. We are spending £10m building car parks to ensure spaces whilst supporting and subsidising alternatives for travel. If you think parking outside the rules was justified, then there is a staff led appeals process."