Open partial horizontal laryngectomy (OPHL) specimens include cartilage and lymph nodes. Pathological adverse findings (PAF): perichondrium, cartilage, perineural invasion, microvessel spread and prelaryngeal metastases can be detected histologically. We aimed at examining PAF in OPHL specimens and examining the interdependence with oncological outcomes. Prospective analysis of 254 glottis cancers: 87-T2a, 77-T2b and 90-T3 with anterior commissure (AC) involvement treated by OPHL at tertiary referral centre between 2001 and 2008. In 38/254 patients (15 %) PAF were found (16 prelaryngeal metastases, 22 other); more often in stage T2b/T3 versus T2a (p = 0.008). PAF other than prelaryngeal metastases were found more often in T2b than T2a tumours (p = 0.005). Outcomes revealed that out of 36 patients with local recurrence, 19 had PAF. Comparison of 216 patients with no PAF and 16 patients with prelaryngeal metastases revealed, respectively: 7.9 versus 81.3 % local recurrences (p = 0.034), 3.2 versus 68.8 % nodal recurrences (p = 0.011), 90.7 versus 43.8 % of 5-year organ preservation (p = 0.021) and 92.6 versus 75 % 5-year overall survival (p = 0.022). Out of 10 patients with close margins, 1 developed the local recurrence; impact for organ preservation and overall survival was not significant. In 22/254 cases including the cartilage into the operating specimen were therapeutically meaningful; in 16/254 with prelaryngeal metastases, the impact for larynx preservation and overall survival was significant. T2b patients had higher probability of PAF than T2a. PAF significantly influenced higher local recurrence rate. This finding ensures the authors, that OPHL type II is not the "overtreatment" compared to the TLM.