Among the possible measures for Information Technology (IT) success is its impact on companies´ performance. Many researches have been conducted to show the influence of IT on firms´ results, but mainly through studies in large-sized firms. The objective of this work is to analyze the relationships between IT investments and organizational efficiency, focusing on micro, small and medium sized enterprises. For this, critical success factors for industrial firms’ performance were identified and a two-stage data envelopment analysis (DEA) model was developed and tested in a sample of firms in the capital goods sector. DEA is especially interesting because it allows comparing and differentiating those firms in the sample which are more efficient in deriving results from IT. Among the results found were the higher capacity of small firms to translate IT investments into operational efficiency and the higher capacity of larger firms to convert critical success factors into profitability.