OBJECTIVES: The aim of a sympathetic blockade is to improve the analgesic response, diminish the opioid consumption, reduces the adverse effects from opioides, and gets efficiency of costs related to treatment. We analyzed the cost-effectiveness of Splanchnic Nerves Blockade (SNB) versus drug therapy in patients with cancer and visceral pain at the upper abdomen. METHODS: A cost-effectiveness analysis was conducted within a retrospective, follow-up study in patients > 18 years with cancer and visceral pain. Using medical records, we assessed patients that underwent a SNB between March 2005 and December 2009. We evaluated the visual analog pain scale (VAS), Karnofsky performance scale (KPS), and medical direct costs. The measures were evaluated before and after (1, 2, 3, 6, 9, and 12 months) the procedure. Cost methodology was calculated trough cost of illness and micro-costing technique, to get the incremental cost-effectiveness ratio (ICER). RESULTS: Sixty-five patients were treated with SNB and 19 with drug treatment-WHO analgesic ladder steps (mean age 52.7±12.9 and 54±12.9, respectively). Basal characteristics were not different between them. VAS scores diminished in both arms, but at repeated measures ANOVA patients on SNB had better pain control (p <0.05) and higher KPS (p<0.05). The mean cost per patient in 1-year follow-up for the drug treatment group was $7,512 MXP (CI 95% $1587-$13,436 MXP), and $5,433 (CI 95% $5,114-$5,752) for SNB. The effectiveness measure was 80% for SNB  vs. 20% for the drug treatment group, respectively. The ICER obtained was negative (-$3526 MXP, IC 95% -5860 to -1191), favoring the SNB as a cost-saving alternative. CONCLUSIONS: SNB showed to be less costly and more effective than drug treatment alone. However, when a sensitive analysis (bootstrap methodology) was conducted the sample size was not powerful enough for a precise CE estimate.