Possibility of the ferroelastoelectric behavior manifestations in a uniaxial ferroelectric TGS crystal was investigated. Analysis of the spontaneous piezoelectric moduli tensors for each of the 180°-domains formed as a result of the phase transition in TGS revealed possible directions for simultaneous application of the electric field and mechanical stresses to induce the switching effect in TGS. Influence of the uniaxial mechanical stresses σ11, σ22, σ33 on the parameters of saturated and unsaturated dielectric hysteresis loops in TGS is considered. It was found that a nontraditional E 3σ12 combination of fields may lead to the domain switching in TGS crystals.