After the very successful Sixth ROOT Users Workshop in September 2005 at CERN we are happy to annouce the Seventh ROOT Users Workshop, to be held at CERN the 26th, 27th and 28th of March 2007. As the use of ROOT continues to grow at a rapid pace it remains important to continue meeting at a regular basis to discuss technical issues, share ideas and plan directions for future development. The main workshop topics are the use of ROOT as a general framework, feedback from experiments, progress with object persistency, merge with SEAL Reflex, progress with the new version of CINT, progress with the Python interface, what is new with the Math libraries, distributed Data Analysis with PROOF, progress with GUIs and graphics, progress with the new GL viewer, progress with the Geometry classes. And much more. Send your presentation (minimum two hours before your talk) to root2007@root.cern.ch. We accept ppt or pdf formats (ppt being preferred). We also invite participants to come with questions, comments, proposals to be discussed in a special Q&A session. The list of participants will be communicated to the Reception office in Building 33. Participants will be guided from the Reception Building or gates A and B towards the Council Chamber. Thanks to Steven Goldfarb and Mitch McLachlan from ATLAS, you can view or download the video archives of all the talks.