Between January 1985 and December 1992, 104 consecutive patients with symptomatic myelofibrosis with myeloid metaplasia (MMM) [splenic enlargement >5 cm and/or transfusional requirement or Hb < 10 g/dl and/or white blood cell (WBC) count >20 x 10(9)/l and/or platelets >1.0 x 10(9)/l] received low-dose Melphalan (2.5 mg/3 times/week) to evaluate the efficacy and toxicity of this approach. Among 99 evaluable patients, 66 (66.7%) achieved a response after a median time of 6.7 months: 26 (26.3%) had a normalization of all clinical and haematological parameters (complete response, CR) and 40 (40.4%) showed an improvement >50% (partial response, PR). Thirty-three patients (33.3%) were resistant. Reversible haematological toxicity was the most common complication. Median durations of CR and PR were 28.4 and 26 months respectively: median survival of CR + PR patients was 71.2 months (95%CI: 33.8-108.7) versus 36.5 months (95%CI: 24.5-48.5) for the non-responders (log-rank test, P =0.002). In the multivariate analysis, the following variables were significantly associated with a shorter survival: anaemia [hazard risk (HR) = 2.7], WBC count >20 x 10(9)/l (HR = 2.4) and not achieving any type of response, either partial or complete (HR = 3.9). In conclusion, Melphalan could be a promising first-line option for MMM patients with clinical or haematological symptoms requiring treatment.