The aim of this study was to examine the effect of progressive sentence development activities on 5th graders' description skills. The study was conducted based on the pretest-posttest quasi-experimental model with a control group. A total of 58 students participated in the study; 29 in the control group, and 29 in the experimental group. The quantitative data were gathered using "Description Skill Scoring Rubric". The "Description Skill Scoring Rubric" was employed as the pre and posttest in the activities in both control and experimental group. The evaluations were carried out by three independent experts. The obtained data were analysed using SPSS. According to the findings revealed from the data, the progressive sentence development activities statistically significantly differentiated the experimental group students' description skills, compared to the students in the control group being exposed to traditional activities. In addition, it was found that the progressive sentence development activities significantly developed the experimental group students' skills of constructing additive and subordinating sentences, and using concretisation, determiners, reduplications, similes and adjectives in the description process. However, there was no significant difference in the pre and posttest scores of the control group students who were exposed to the traditional method. In the learning-teaching process, it can be argued that students should be the primary element of activities. In this sense, the progressive sentence development activities which give students the opportunity to participate in the lessons effectively should be emphasized in the teaching process.