Objective To evaluate the impact of extracapsular spread （ECS） in ipsilateral neck metastasis on prognosis and its related factors in laryngeal cancer. Methods The study included 184 patients who underwent laryngectomy and simultaneous radical or modified radical neck dissection between January 1994 and December 1997 for laryngeal cancer. All of them had a complete 5-year follow-up. We used transparent lymph node detection and continuous slicing method on all neck dissection specimens. Kaplan-Meier model was used for survival analysis and the log-rank test was used to assess significance. Results We found pathological neck metastases in 80 patients. Among them

26 cases （32.5%） had ECS in ipsilateral neck. ECS incidence increased with advanced pathological N （pN） stages （pN1 3.7%

pN2a 25.0%

pN2b 50.0%

and pN2c 55.6%; P=0.001）. ECS incidence also increased with number of positive nodes （1 positive node 8.6%

2 positive nodes 33.3%

3 and more positive nodes 66.7%; P<0.001）. Incidences of contralateral neck metastases and ipsilateral neck recurrence in patients with ECS were higher than those in patients without ECS （46.2% vs. 24.1%

P=0.046; 34.6% vs. 7.4%

P=0.002）. The 5-year survival rate of patients with ECS was significantly lower than that of patients without ECS （23.1% vs. 57.4%

P=0.013）. Conclusion ECS is an important prognostic factor in laryngeal cancer. Patients with ECS have a higher incidence of contralateral neck metastasis

so bilateral neck dissection should be selected.