The nucleation stage of secondary recrystallization has never been considered in detail. During the present study, nucleation of abnormal grain growth in ULC steel was studied. A specific nucleation mechanism was identified. This mechanism involved the disappearance of low angle grain boundaries, which gave rise to the onset of a local grain coalescence mechanism that clusters grains that were only separated by low angle grain boundaries. The impact of the nucleation stage remained visible in the texture that was obtained after complete abnormal grain growth.