Progressive pseudo-rheumatoid dysplasia is an autosomal recessive skeletal dysplasia. Spine radiographs show platyspondyly. The clinical presentations are similar to juvenile idiopathic arthritis, but not the laboratory findings. We report 2 cases of progressive pseudo-rheumatoid dysplasia in the same family. A 26 years old male was admitted in the department of Rheumatology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with the complain of inflammatory joint pain, joint swelling, range-of-motion limitation, and joint deformities in the hands, wrists, ankles, knees and hips for 20 years. He was treated as juvenile idiopathic arthritis with different anti-inflammatory medications having progressing by flares and remissions. Erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, anti ccp antibody and HLAB27 levels were normal. Synovial fluid of the knees showed mechanical properties. Plain radiographs of the hands and knees showed evidence of joint destruction. Radiograph of the pelvis notes bilateral hip dysplasia. Platyspondyly was found in spinal radiograph. The diagnosis of juvenile idiopathic arthritis was reconsidered. His 22 years old younger brother had similar manifestations without laboratory evidence of inflammation; radiographs disclosed dysplasia of the hips and metacarpophalangeal epiphyses. Manifestation of spinal stiffness, thoracic kyphosis, and motion-range limitation at the hips; radiographs showed normal sacroiliac joints and bilateral hip dysplasia. So, a diagnosis of progressive pseudo-rheumatoid dysplasia with polyarticular involvement was done.