We discuss the monitoring of tuberculosis treatment outcomes and the adherence of countries in the WHO European Region to changes introduced in 2001 to improve comparability across countries. Outcomes for confirmed pulmonary tuberculosis cases were compared for cases reported in 2001 and 2000. Reporting was considered complete if 98% or more of the cases originally reported had an outcome recorded. In both years, the maximum observation period was 12 months from the start of treatment. In 2000, countries reported outcomes as “cured,” “completed,” “died,” “failed,” “defaulted,” “transferred,” and “other, not evaluated” for cohorts of new and retreatment cases. In 2001, following changes, countries were also asked to monitor cases with unknown treatment history, and two outcome categories were added: “still on treatment” and “unknown.” Of the 42 countries reporting outcomes in 2001, 74% (31) had complete, nationwide data, up from 50% (19 out of 38) in 2000. Twelve of 21 countries that reported on the observation period complied with the recommendation. "Defaulted" and "transferred" were used interchangeably with "unknown." Among new cases, "still on treatment" was used by 15 of 31 countries (range: 1%–15%). "Failed" was rarely recorded in Western European countries (<1%). European tuberculosis outcome monitoring should include all definite pulmonary cases, applying the standard observation period and revised categories, and preferably reported using individual data. (R.A.)