Background. Initiatives to improve early detection and access to human immunodeficiency virus (HIV) services have increased over time. We assessed the immune status of patients at initial presentation for HIV care from 1997 to 2007 in 13 US and Canadian clinical cohorts. Methods. We analyzed data from 44,491 HIV-infected patients enrolled in the North American-AIDS Cohort Collaboration on Research and Design. We identified first presentation for HIV care as the time of first CD4- T lymphocyte (CD4) count and excluded patients who prior to this date had HIV RNA measurements, evidence of antiretroviral exposure, or a history of AIDS-defining illness. Trends in mean CD4 count (measured as cells/mm3) and 95% confidence intervals were determined using linear regression adjusted for age, sex, race/ethnicity, HIV transmission risk, and cohort. Results. Median age at first presentation for HIV care increased over time (range, 40-43 years; P< .01), whereas the percentage of patients with injection drug use HIV transmission risk decreased (from 26% to 14%; P<.01) and heterosexual transmission risk increased (from 16% to 23%; P<.01). Median CD4 count at presentation increased from 256 cells/mm 3 (interquartile range, 96-455 cells/mm3) to 317 cells/mm3 (interquartile range, 135517 cells/mm3) from 1997 to 2007 (P < .01). The percentage of patients with a CD4 count 3=350 cells/mm3 at first presentation also increased from 1997 to 2007 (from 38% to 46%; P<.01). The estimated adjusted mean CD4 count increased at a rate of 6 cells/mm3 per year (95% confidence interval, 5-7 cells/mm3 per year). Conclusion. CD4 count at first presentation for HIV care has increased annually over the past 11 years but has remained <350 cells/mm3, which suggests the urgent need for earlier HIV diagnosis and treatment. © 2010 by the Infectious Diseases Society of America. All rights reserved.