Women legislators can only exert equal influence in parliaments when they receive the same respect and opportunities as men. This requires that elected women have equal chances to voice their opinions, and that their perspectives are being heard. This study demonstrates that the second requirement is not self-evident. We analyze televised parliamentary recordings to trace legislators’ attention during more than 25,000 speaker-listener interactions in a large German state parliament (2018--2019). Our findings indicate a critical problem for women's equitable participation in parliamentary deliberation: Women receive systematically less attention for their contributions than men. This disparity is fully attributable to men in the audience who pay less attention to speeches by women. In contrast, women give equal attention to speeches by men and women. These results shed light on the so far underappreciated role of interpersonal attention as a barrier to the equitable participation of women in political deliberations.