<p class="E-JOURNALTitle">Penelitian ini bertujuan untuk mendeskripsikan: (1) pengaruh model <em>Problem Based Learning </em>(PBL) terhadap kemampuan komunikasi matematika; (2) pengaruh model PBL terhadap kemampuan pemecahan masalah matematika; dan (3) pengaruh model PBL terhadap kemampuan komunikasi dan pemecahan masalah matematika secara bersama-sama. Jenis penelitian yang digunakan yaitu kuasi eksperimen dengan desain <em>Pretest-Posttest Control Group Design</em>. Populasi penelitian ini adalah seluruh siswa kelas V SDN se-Gugus V Kecamatan Kasihan Bantul. Pengambilan sampel menggunakan teknik <em>Cluster Random Sampling</em><em>.</em><em> </em>Instrumen yang digunakan untuk mengumpulkan data berupa tes uraian objektif. Teknik analisis data yang digunakan meliputi analisis deskriptif dan analisis inferensial, untuk analisis inferensial menggunakan <em>independent sample t-test, </em>uji MANOVA dengan rumus <em>T<sup>2</sup> Hotelling</em>, dan dilanjutkan dengan uji kriteria Bonferroni. Hasil penelitian menunjukkan bahwa (1) model PBL berpengaruh positif dan signifikan terhadap kemampuan komunikasi matematika dengan nilai signifikansi lebih kecil dari 0,025; (2) model PBL berpengaruh positif dan signifikan terhadap kemampuan pemecahan masalah matematika terhadap kemampuan pemecahan masalah matematika dengan nilai signifikansi lebih kecil dari 0,025; (3) model PBL berpengaruh positif dan signifikan terhadap kemampuan komunikasi dan pemecahan masalah matematika secara bersama-sama dengan nilai signifikansi lebih kecil dari 0,05.</p><p class="E-JOURNALAbstrakKeywords"><strong>Kata Kunci</strong>: model PBL, kemampuan komunikasi matematika, dan kemampuan pemecahan masalah matematika</p><p class="E-JOURNALTitleEnglish"> </p><p class="E-JOURNALTitleEnglish"><strong>THE EFFECTS OF THE PBL MODEL ON THE MATHEMATICAL COMMUNICATION AND PROBLEM-SOLVING SKILLS OF FIVE-GRADERS OF ELEMENTARY SCHOOL STUDENTS</strong></p><p class="E-JOURNALAbstrakTitle"><strong><em>Abstract</em></strong></p><p class="E-JOURNALAbstractBodyEnglish">This research aims to describe: (1) the effects of the Problem Based Learning (PBL) model on the mathematical communication skills; (2) the effects of the PBL model on the mathematical problem-solving skills; and (3) the effects of the PBL model on both the mathematical communication skills and the mathematical problem-solving skills simultaneously. The research of this study was quasi-experimental with pretest-posttest control group design. The research population consisted of five-graders of all elementary schools located in Group V of Kasihan District, Bantul. The sample was collected using the cluster random sampling technique. The data were analyzed by descriptive and inferential technique which is using independent sample t-test, MANOVA with Hotelling’s trace formula, and the last was by Bonferroni criteria. The findings suggest that: (1) the PBL model positively and significantly affects the mathematical communication skills with a significance value of less than 0.025; (2) the PBL model positively and significantly affects the mathematical problem-solving skills with a significance value of less than 0.025; (3) the PBL model positively and significantly affects both the mathematical communication skills and the mathematical problem-solving skills simultaneously with a significance value of less than 0.05.</p><strong>Keywords</strong>: the PBL model, mathematical communication skills, and mathematical problem-solving skills.