Background: Pressure ulcer is a chronic wound that has a high prevalence. Despite all the efforts, pressure ulcers closure of tentimes fail. A tool is required to establish the right moment for wound closure. The presence of bacteria is one of the big factors that interfere with the wound healing process.The type and number of certain bacterial load also determine the success of wound closure. Objectives: We propose a solution by using the bacterial type and number measurement to determine wound closure success in pressure ulcers. Methods: This was a hospital-based nested case-control study at Hasan Sadikin General Hospital, Bandung. Data were collected from April 2012 to February 2014. The relationship between variables was analyzed with bivariate analysis, while its strength was assessed by the contingency coefficient. Results: Twenty-four patients who underwent wound closure were enrolled as respondents. The relationship of bacterial types with the success rate of pressure ulcer closure did not show significant differences (P-value = 0.921). The bacteria quantity in the group that succeeded and failed also did not show a significant difference (P-value = 0.995). However, the combination of type and number of bacteria were significantly different between the successful and unsuccessful group (P-value = 0.034; C = 0.653). Conclusion: The success rate of pressure ulcer closure determined by both the number and type of bacteria, not separately. Thus, it is important that surgeons perform both tests on preoperative pressure ulcer patients due to their proven benefits in predicting the success rate of surgical closure.