This is a phase II study in relapsed/refractory WM patients treated with perifosine. It is designed to assess the proportion of overall confirmed responses (CR + PR + MR) using a two-stage phase II study design to permit early stopping of the trial if there is strong evidence that the study regimen is inactive. In addition, it will assess toxicity of this drug in patients with WM. Patients will receive perifosine 150 mg qhs daily. Patients will be assessed by serum immunoelectrophoresis and IgM level at least every 4 weeks.