This case describes a posterior fossa mass due to blastomycotic infection in a non-immunocompromised 41-year-old male presenting with a chronic headache for over one year. Given the risk of herniation, no lumbar puncture could be performed. A full work-up found no evidence of systemic infection. Surgical resection helped identify the mass as a blastomycotic abscess. Magnetic resonance imaging characteristics of the mass were helpful in the identification of the mass as a fungal abscess