Cement compositions that include improved lost circulation materials are provided. In certain exemplary embodiments, the improved lost circulation materials include inelastic particles of polyethylene, polystyrene, and/or polypropylene. Optionally, the cement compositions also may include additives such as fly ash, a surfactant, a dispersant, a fluid loss control additive, a conventional lost circulation material, an accelerator, a retarder, a salt, a mica, fiber, a formation-conditioning agent, fumed silica, bentonite, expanding additives, microspheres, weighting materials, or a defoamer.