Objective: To evaluate the direct costs of transforaminal lumbar interbody fusion (TLIF) and minimally invasive surgery (MIS) or open technique (OPEN). Methods: The present study is descriptive and retrospective. Sixteen patients with degenerative spinal pathology operated on with the TLIF MIS technique and TLIF OPEN were included over a 13-month period. Days of hospital stay, blood loss, surgical time, medical care and costs were compared. Results: The mean number of days of hospital stay was 6.7 ± 4.3 days with TLIF MIS and 11.1 ± 6.5 days with TLIF OPEN. The blood loss was 307 ± 81.6 ml (range 200-400 ml) with TLIF MIS and 803 ± 701.3 ml (range 200-1800 ml) with TLIF OPEN. The surgical time was 320 ± 92.6 minutes (range 210-500 minutes) in TLIF MIS and 372 ± 95.2 minutes (280-540 minutes) in TLIF OPEN. Conclusions: The difference in surgical costs and time between the two procedures was not statistically significant. There was less bleeding during the TLIF-MIS surgery, as well as a correlation between shorter days of hospital stay proportional to bleeding and surgical time, which translates into a reduction in the cost of these items. Level of Evidence III; Analysis based on alternatives and limited costs.Keywords: Intervertebral disc degeneration; Spinal fusion; Arthrodesis. de 6,7 ± 4,3 días con TLIF MIS y de 11,1 ± 6,5 días con TLIF OPEN. La pérdida sanguínea fue de 307 ± 81, con TLIF MIS y de 803 ± 701,3 ml (rango 200-1800 ml) RESUMO Objetivo: Garantir benefícios econômicos diretos de cada procedimento cirúrgico. Metodologia: apresentar um estudo descritivo e retrospectivo. Dezesseis pacientes com patologia degenerativa de colônias operados com a técnica TLIF MIS e TLIF OPEN foram incluídos durante um período de 13 meses. Foram comparados os dias de internação RESUMEN Objetivo: Evaluar los costos directos de la fusión intersomática lumbar transforaminal (TLIF) de mínima invasión (MIS) o técnica abierta (OPEN). Métodos: El presente estudio es descriptivo y retrospectivo. Se incluyeron 16 pacientes con patología degenerativa de columna intervenidos con la técnica TLIF MIS y TLIF OPEN en un período de 13 meses. Se compararon días de estancia hospitalaria, pérdida sanguínea, tiempo quirúrgico, atención médica y costos. Resultados: La media de días de estancia hospitalaria fue