LGB is the standard acronym for Lehmann Gross Bahn - the "Lehmann Big Train" in German. Made by Ernst Paul Lehmann Patentwerk in Nuremberg, Germany, since 1968, it is the most popular garden railway models in Europe, although there are also many models of U.S. and Canadian prototypes. LGB caused a revival of garden model railroading in the United States when it was introduced. LGB was sold in North America through Ernst Paul Lehmann's subsidiary, LGB of America. Most of the European prototypes were manufactured in Germany, while much of the North American rolling stock was made in China.

LGB trains are responsible for introducing "G" scale to model railroading. The scale ratio used by LGB is 1:22.5, although other G-scale (and Gauge 1) manufacturers produce products that range from 1:20 to 1:32, and for the most part, all use the same track and are compatible with one another. Though they can all run on the same track (45 mm gauge), it should be noted, however, that models representing narrow-gauge versions of trains or locomotives would not normally be run together with models of larger full-scale vehicles. To fit the same standard track the latter must be built using different scales. To illustrate the point, 1:22.5 scale passengers and/or train crew are somewhat oversized when displayed in close proximity with 1:32 models. Though the models may be physically compatible, many people choose a style or era to fit their desires and pick one ratio (in the range of 1:20.3 to 1:32) to model all of their trains.

One of the most prominent aspects of LGB trains over other model railroad models is their durability. All locomotives, track, and accessories of the main product line function in rain and snow allowing nearly anyone to have an outdoor garden railroad. As a matter of fact, there have been cases when LGB products have survived against all odds. Apparently, an LGB controller was once caught in a flood in early spring; not only was it completely submerged, but the water actually froze solid around it the next day when the temperature dropped. After the controller thawed out, it was taken inside and set next to a heater to dry. Against all odds, the product apparently worked fine, as if nothing had happened.

The first loco made under the LGB brand was a model of a small Austrian 0-4-0 named "Stainz." This loco appears in the LGB logo and is still in production today, although it now has a sound system and other mechanical differences to the original 1968 model. Most garden railway enthusiasts have at least one example of a Stainz in their collection as it tends to be a robust loco with good pulling power.

LGB's tooling is of great interest due to its design. For example, on the standard 4-wheel coach they have a choice four roof designs and three body designs, all using the same chassis and end walkway moldings. Such careful planning allows common parts to be used keeping costs down. Two very different-looking vehicles can share all but one or two components. LGB's engineering is also of similar interest. Starter sets typically include a circle of track with a 4 foot diameter and a smaller two-axle locomotive, like the Stainz mentioned above.