Leather tanning industry produces large amounts of solid wastes. Chrome tanned leather shaving waste (CTLS) is about 20% of these solid wastes, which has not been utilized in Egypt and causing environmental hazards and economic loss. This current work investigates the properties of new gypsum composite materials containing different percentages of CTLS, ranging between 0% and 25%. The physical-mechanical characteristics for prepared composites were determined and the construction morphology was analyzed by scanning electron microscopy (SEM). The experimental results show that significant reductions of composite density (from 2.1 to 1.35 t/m³), compressive strength (from 7.0 to 2.7 MPa), flexural strength (from 4.5 to 2.2 MPa) and thermal conductivity (from 0.60 to 0.19 W/m°C) occurred with increasing CTLS content (from 0 to 25%), respectively. Thermal conductivity of CTLS-gypsum composite especially at high content of CTLS allowed us to use this formulation as a separations or filling materials in buildings to increase the thermal insulation. SEM micrograph of the CTLS-gypsum composite shows homogeneous and complex structures with good interaction between CTLS and gypsum.