This study explores the integration of an in-line analytical balance into a GMP pharmaceutical 3D printer to automate mass uniformity testing of 3D printed medicines. The authors developed a specialized software-controlled weighing system that integrates with the M3DIMAKER 1 pharmaceutical 3D printer. Three batches of hydrocortisone pharma-ink printlets (n = 28) were printed and subjected to in-line mass uniformity testing. The software accurately registered the weights of all individual printlets and detected any deviations within the accepted limits. Only one printlet was outside the accepted weight range, likely due to the first print being imperfect. The weights obtained from the integrated balance were compared with those from an external analytical balance, showing no significant differences. This study is the first to integrate an analytical balance inside a pharmaceutical printer, automating mass uniformity testing and improving the quality control of 3D printed pharmaceuticals. The automated process saves time, labor, and resources while ensuring compliance with regulatory requirements.This study explores the integration of an in-line analytical balance into a GMP pharmaceutical 3D printer to automate mass uniformity testing of 3D printed medicines. The authors developed a specialized software-controlled weighing system that integrates with the M3DIMAKER 1 pharmaceutical 3D printer. Three batches of hydrocortisone pharma-ink printlets (n = 28) were printed and subjected to in-line mass uniformity testing. The software accurately registered the weights of all individual printlets and detected any deviations within the accepted limits. Only one printlet was outside the accepted weight range, likely due to the first print being imperfect. The weights obtained from the integrated balance were compared with those from an external analytical balance, showing no significant differences. This study is the first to integrate an analytical balance inside a pharmaceutical printer, automating mass uniformity testing and improving the quality control of 3D printed pharmaceuticals. The automated process saves time, labor, and resources while ensuring compliance with regulatory requirements.