Four cases of venous malformation associated with a cavernous malformation are reported. Because cavernous malformations are often angiographically occult and do not have a characteristic appearance on computed tomography (CT), they are seldom recognized preoperatively and may be missed if the surgical specimen is not carefully reviewed. This association, however, may not be rare and may explain the presence of symptomatic venous malformations. Magnetic resonance (MR) imaging is particularly sensitive in detecting cavernous malformations and is highly specific. It is recommended that every symptomatic venous malformation be worked-up with a high field strength MR Unit.