Unsustainable exploration of natural resources in protected areas has increased in global scale and at accelerated rate in the 21st century, mainly in tropical regions such as South America. This scenario has worried the scientific community due to the risk of biodiversity and ecosystem functions loss, which raises a common and growing sense of the need to inspect and maintaining those areas. In this context, the central objective of this work was to evaluate the management effectiveness of national parks in Peru. For this, scenario matrix methodology was employed, which is based on a questionnaire that is applied to park managers. The methodology establishes possible scenarios based on a set of indicators, which allows evaluating park management effectiveness from unsatisfactory to satisfactory. Most parks (6 or 55%) showed medium management effectiveness, while 45% (5 parks) presented satisfactory management effectiveness. This result is explained by the positive performance of some indicators (expropriation, relationship with the surroundings, protection and inspection programs, as well as management plan). In addition, no specific indicator significantly influenced management effectiveness (no significant difference among the effect of considered indicators). Our results indicate that Peru's national parks are currently well managed. However, some indicators need to be improved, especially for parks that showed medium management effectiveness. Furthermore, this study can help managers to maintain and allocate financial resources in protected areas with greater precision, since scenario matrix methodology allows the identification of low performance indicators.