<span style="font-size: 10px;">Curriculum 2013 is one form of reformation and innovation of education in Indonesia. Authentic assessment is one of the essential elements that must be implemented in the learning process. This study aims to determine the implementation of authentic assessment on PAI learning and knowing the constraints faced by PAI teachers in implementing them in MTsN 2 Palangkaraya. This research is a qualitative descriptive study, by using observation, interviews, and documentation as techniques of collecting the data. Then, the data were analyzed through data reduction, data presentation, and conclusion. To check the data trustworthiness, the researher used persistence observation, triangulation, and inspection peers through discussion. The results showed that: 1) Implementation of Curriculum 2013 authentic assessment conducted by the teacher PAI in MTsN 2 Palangkaraya didnot run optimally; 2) the problems of PAI teachers in implementing is in common constraints and special constraints. A common constraint is the availability of books in supporting learning. While the special constraints are the ability of teachers about the technical problems related to the ability of teachers to use assessment application; and the non-technical constraints, it is the ability of teachers to understand authentic assessment itself. </span>