This research study investigated the difficulties in performance task authentic assessment encountered by Junior and Senior High School Social Studies Teachers of Zone 2, DepEd Schools Division of Zambales during the school year 2019. This research study employed descriptive research designs with the questionnaire as the main source of gathering the data from 127 teacher-respondents. The results revealed that the teacher-respondent is female in her early adulthood, Social Studies major, Teacher-1 and BS degree with Master’s units. As for the result of the problems encountered in the performance task authentic assessment, the teacher-respondents never observed a problem in determining the assessment criteria. However, the teacher respondents sometimes encountered problems in the aspects of utilizing the performance tasks and assessing the performance task respectively. The computed Analysis of Variance resulted in a significant difference of perception when grouped according to highest educational attainment towards determining the assessment criteria; significant in age towards utilizing the performance tasks and no significant difference in all profile variables towards assessing the performance tasks. Based on the conclusions arrived at, the researcher has offered the following recommendations such as the school administrator is encouraged to propose an in-service training for teachers on the enhancement of capabilities in assessing the student outputs and performances; the students should be well-informed and be included in the formulation of criteria for evaluation and should be provided with information on the result of every assessment activity; and that the teachers in all assessment activity should practice with utmost fairness and objectivity in assessing the student performances.