The aim of this study was to investigate the effectiveness of the attention training technique(ATT) on the frequency of intrusive thoughts experienced by a person with schizophrenia in her daily life. The attentional procedure was designed to attenuate self-focused attention and to reinforce attentional control and consisted of auditory external exercises. Homework practice was included to promote transfer to everyday life. The efficacy and specificity of the ATT were assessed with cognitive, functional, and control measures. The impact of ATT on symptomatology, work functioning, and self-esteem was also measured. Postrehabilitation results showed that, after nine training sessions, there was a reduction in intrusive thoughts for the cognitive and ecological outcome measures. Selective attention, attention switching, and resistance to distractive interference specifically improved. The person reported a reduction in intrusive thoughts in her daily life. In addition, positive symptoms decreased. Finally, a 6-month follow-up assessment revealed the maintenance of most of the beneficial effects in daily life.