The Pramanavarttikalamkara of Prajnakaragupta is a commentary on Dharmakirti’s Pramanavarttika. A manuscript of the text in Sanskrit was discovered by Rahula Sankrtyayana, and the same scholar published its first edition in 1953. Since this editio princeps was made without using all available materials and since the methodological procedures are unsatisfying in many other respects, too, any further reflection on the thoughts and ideas of Prajnakaragupta presupposes a new critical edition. Ono’s work is a well done first step in that direction. The edited text comprises the first section of the Pramanavarttikalamkara, which is concerned with the definition of valid cognition. Besides the manuscript, the Tibetan translation and the commentaries, use has been made of all other available sources, including on first place secondary testimonies.