Theoretical methods are used to analyze the thermodynamics of ZSM-11 synthesis from amorphous silica and an aqueous solution of tetraalkylammonium hydroxide (TAAOH). The overall process is represented by the reaction 96SiO(2)(a) + n(TAA(+)/OH-/200H(2)O) = (nTAA(+)/Z(n-)) + 200nH(2)O. Both tetrapropylammonium (TPA(+)) and tetrabutylammonium (TBA(+)) cations are considered as the structure-directing agents, and calculations are performed for occlusion of either three or four TAA(+) cations per unit cell of the zeolite. Both estimates of the change in internal energy and Gibbs free energy reveal that the synthesis of ZSM-11 should be favored by the occlusion of three TBA(+) cations per unit cell, consistent with experimental observation. The present analysis also demonstrates the importance of energy and entropy changes associated with the dehydration of TAA(+) and OH- ions and with the occlusion of TAA(+) cations into the zeolite. The interactions of OH- anions with the zeolite framework to form defects in the form of siloxy (=SiO-) groups are also considered.