The LABOCA Extended Chandra Deep Field South (ECDFS) Submillimetre Survey (LESS) is a public legacy survey of the ECDFS at 870 μm using the LABOCA camera (Siringo et al. 2009) on the APEX telescope. <p> The LABOCA data presented here were obtained between 2007 May and 2008 November in excellent conditions using time from both ESO and Max Planck allocations. The mapping pattern was designed to uniformly cover the 30'x30' extent of the ECDFS, centered on 03:32:29.0, -27:48:47.0 (J2000). The project used a total of 310 hrs of observations to achieve a beam-smoothed noise of 1.2 mJy/beam over 900 sq. arcmin (and <1.6mJy/beam over 1260 sq. arcmin). The flux calibration of the map came from observations of Mars, Uranus and Neptune (as well as secondary calibrators) and is accurate to within 8.5%. Provenance: Data downloaded from ESO archive. This is a service of NASA HEASARC.