The study aimed at developing the required EFL critical writing skills for 2^nd year secondary school students through using scaffolding with online tasks. Participants of the study were randomly selected and divided into two groups(31 for the experimental group and 31 for the control group). The study employed a critical writing  skills test and a critical writing skills rubric. The necessary critical writing skills for 2^nd year secondary school students were determined through the use of a checklist approved by a jury of specialists in teaching EFL.  During the experiment, the experimental group received instruction through using scaffolding  with online tasks, while the control group received regular instruction. The experiment lasted for two months. The analytical descriptive method and quasi experimental design were followed. The statistical analysis of the obtained data from the  administrations of the test confirmed the effect of scaffolding with online tasks  on developing critical writing skillsfor 2^nd year secondary school students .Thus ,the aim of the study was  achieved as using scaffolding with online tasks  showed a large effect size on developing the critical writing skills for the experimental group of the participants . Based on the results, it was recommended that teachers should give due attention to the development of critical writing skills in EFL classes through online scaffolding tasks .In addition, using scaffolding in developing other language skills was suggested.