Yes, is it definitly possible. However, as this page states:
Producing physical prints from our provided 3D models prompts certain fabrication considerations. According to Wikipedia, the precision of Lego pieces is less than 10 microns. As of early 2012, however, standard Makerbot printers have an XY resolution of 100 microns (0.1mm) and a default layer thickness of 360 microns (0.36mm). We thus caution that fabrication of the Free Universal Construction Kit with current (2012-era) solutions for DIY stereolithography, such as the Makerbot, Printrbot or RepRap, may lack the precision required for reliable or satisfactory coupling with standard commercial pieces. A great deal depends on how well-tuned the printer is; thus, your mileage may vary. In any case, we expect this situation will improve gradually, but inexorably, in tandem with improvements to these vibrantly evolving fabrication platforms. The artist’s proof shown here was created in a UV-cured white resin using a commercial-grade Objet (“polyjet”) 3D printer, which has a horizontal resolution of 42 microns, and a layer thickness of 16 microns. Ponoko.com and other private fabrication services offer printing from Objet machines and other high-resolution devices.
Free Art and Technology [F.A.T.] Lab and Sy-Lab. “The Free Universal Construction Kit.” Fffff.at, 20 March 2012. http://fffff.at/free-universal-construction-kit.
The article cited deals with a universal construction kit that allows you to connect ten diffent types of construction sets together, and as this is a Lego site, you may not want to visit it.
However, the point being that "standard" 3D printers (such as the Makerbot or RepRap) will probably lack the precision to produce tolerable Lego bricks.