Inclusion Criteria:

- Are 18 years of age or older

- Have NSCLC, Stage IIIa/b or IV, that is not amenable to curative therapy

- Have had one prior chemotherapy regimen with cytotoxic agents for the treatment of
NSCLC (patients with adjuvant and neoadjuvant regimens are also eligible. However,
patients with one prior cytotoxic chemotherapy followed by a targeted agent such as
erlotinib are not eligible because the targeted agent would be regarded as
second-line treatment)

- Are initiating second-line of treatment for NSCLC with pemetrexed

- Have been fully informed and have given written consent for the use of their data.

Exclusion Criteria:

- Have received any prior treatment with pemetrexed

- Are participating in a study including administration of any investigational drug or
procedure at entry into this study