Background: Current information on the prevalence and etiology of male infertility comes from non-Latino(NLM), relatively high socioeconomic status(SES) Caucasian male populations referred primarily to private practice urology services. The prevalence of azoospermia in the general male population is 2-4%, whereas it is a much higher 10-20% in referred male infertility patients. Approximately 60% of those are diagnosed with non-obstructive azoospermia(NOA) and 40% with obstructive azoospermia(OA). Data on non-affluent males, particularly Latino males(LM), is lacking, despite the fact that this minority comprises over 13% of the US and 50% of the Los Angeles County populations.Objective: To determine the prevalence and etiology of azoospermia in a non-referral inner-city infertility population.Materials and Methods: Semen analysis is routinely performed in partners of all women evaluated at the LAC-USC Women’s and Children’s Hospital Endocrine/Infertility Clinic. Men found to have azoospermia or oligospermia (concentration<20x106/ml) are referred to the male infertility clinic. All azoospermic patients evaluated in this clinic from January 1, 1999 to August 31, 2004 were identified. OA or NOA was diagnosed based on history, physical, and laboratory evaluation. In the absence of a testicular biopsy, OA diagnosis was based on accepted criteria of normal hormone values and testicular volumes (≥15 ml/testicle) with low seminal fluid volume (<1.5ml).Tabled 1DIAGNOSISNo. (%) n=53Obstructive Azoospermia (OA)3 (6)Nonobstructive Azoospermia (NOA)50 (94)Primary Germ Cell Failure5 (9)Testicular Failure16 (30)Sertoli-cell Only1 (2)Hypogonadotropic Hypogonadism5 (9)Idiopathic23 (43) Open table in a new tab Conclusions: This is the first known report on azoospermia in a predominantly Latino, inner-city population. Although our prevalence of azoospermia was similar to that reported in more affluent populations, we found a higher incidence of NOA in patients presenting for screening semen analysis. These data suggest that NOA is the predominant cause of azoospermia, which may be explained by occupational and/or environmental toxic exposures, genetic/physiologic differences, or SES related issues. Our findings highlight the need for further study of ethnic, physiologic, cultural and sociologic differences in the incidence and etiology of male infertility. Background: Current information on the prevalence and etiology of male infertility comes from non-Latino(NLM), relatively high socioeconomic status(SES) Caucasian male populations referred primarily to private practice urology services. The prevalence of azoospermia in the general male population is 2-4%, whereas it is a much higher 10-20% in referred male infertility patients. Approximately 60% of those are diagnosed with non-obstructive azoospermia(NOA) and 40% with obstructive azoospermia(OA). Data on non-affluent males, particularly Latino males(LM), is lacking, despite the fact that this minority comprises over 13% of the US and 50% of the Los Angeles County populations. Objective: To determine the prevalence and etiology of azoospermia in a non-referral inner-city infertility population. Materials and Methods: Semen analysis is routinely performed in partners of all women evaluated at the LAC-USC Women’s and Children’s Hospital Endocrine/Infertility Clinic. Men found to have azoospermia or oligospermia (concentration<20x106/ml) are referred to the male infertility clinic. All azoospermic patients evaluated in this clinic from January 1, 1999 to August 31, 2004 were identified. OA or NOA was diagnosed based on history, physical, and laboratory evaluation. In the absence of a testicular biopsy, OA diagnosis was based on accepted criteria of normal hormone values and testicular volumes (≥15 ml/testicle) with low seminal fluid volume (<1.5ml). Conclusions: This is the first known report on azoospermia in a predominantly Latino, inner-city population. Although our prevalence of azoospermia was similar to that reported in more affluent populations, we found a higher incidence of NOA in patients presenting for screening semen analysis. These data suggest that NOA is the predominant cause of azoospermia, which may be explained by occupational and/or environmental toxic exposures, genetic/physiologic differences, or SES related issues. Our findings highlight the need for further study of ethnic, physiologic, cultural and sociologic differences in the incidence and etiology of male infertility.