Compressive spectral imaging enables to reconstruct the entire three-dimensional (3D) spectral cube from a few multiplexed images. Here, we develop a novel compressive spectral imaging technique using diffractive lenses. Our technique uses a coded aperture to spatially modulate the optical field from the scene and a diffractive lens such as a photon-sieve for dispersion. The coded field is passed through the diffractive lens and then measured at a few planes using a monochrome detector. The 3D spectral cube is then reconstructed from these highly compressed measurements through sparse recovery. A fast sparse recovery method is developed to solve this large-scale inverse problem. The imaging performance is illustrated at visible regime for various scenarios with different compression ratios through numerical simulations. The results demonstrate that promising reconstruction performance can be achieved with as little as two measurements. This opens up new possibilities for high resolution spectral imaging with low-cost and simple designs.