The knowledge of prognostic factors capable of subdividing cancer patients into groups having homogenous survival times is useful even in very advanced stages of illness. This prospective multicenter study assessed these prognostic factors in 530 terminal patients with solid tumors who were undergoing only palliative care. Thirteen hematological and urinary parameters were assessed on admission and every 28 days thereafter. In 519 assessable patients with a median survival of 32 days, six biological parameters demonstrated a statistically significant predictive prognosis. A poor prognosis was predicted by high total white blood count (WBC) (P < 0.0001), high neutrophil percentage (P < 0.0001), low lymphocyte percentage (P < 0.0001), low serum albumin level (P = 0.0015), low pseudocholinesterase level (P < 0.0001), and high proteinuria (P = 0.0064). Multiple regression analysis showed that only WBC, lymphocyte percentage and pseudocholinesterase level were independent predictors of survival. The individualization of biological parameters having an independent prognostic capacity is a useful step in the attempt to identify subsets of patients with a homogeneous prognosis. The biological factors needed are easily detected by means of a simple blood test and do not require invasive operations on patients who are already debilitated.