To investigate the microstructure-dependent relationships in polycrystalline Ni-based superalloys (Haynes 282 and Inconel 718) deformed in the elastoplastic regime, the lattice strain evolution along various macroscopic directions and along various crystallographic directions is monitored via in situ neutron diffraction during uniaxial tensile loading. In addition, a crystal plasticity-based finite element model is set up to describe the micromechanical behaviour of a unit cell within a uniaxially loaded polycrystalline aggregate. Appropriate postprocessing of the (micromechanical) field quantities allows to simulate the diffraction experiment and thus to directly compare and to discuss experimental and modelling results.