To better understand risk factors associated with current asthma in a low-income, ethnically diverse population, we analyzed pooled data from the 2004-2006 Behavioral Risk Factor Surveillance System survey conducted in Salinas, CA. We were particularly interested in modifiable risk factors, as the survey was conducted as part of a large community-based intervention that addresses asthma, obesity, and diabetes. We also conducted semi-structured interviews with key informants involved with the clinical, school, and community aspects of the intervention to inform the intervention's progress, and adapt practices and programs to reach those most in need. Of the 4925 adults in this analysis, 51% were Mexican-American and 32% lacked a high-school diploma; 227 women and 84 men had current asthma, and 194 were parents of children with current asthma; prevalences of 7.7%, 4.3%, and 7.0% respectively. Over 20% of women and men with asthma were current smokers and/or exposed to passive smoking, more than 50% reported less than the recommended 60 minutes or more of physical activity per day, and approximately 40% were obese or morbidly obese (42% of women and 36% of men compared to 26% of adults without asthma). Two of the strongest modifiable risk factors associated with current asthma and identified by the stepwise multiple regression models were: could not afford prescription medication(s) in the past 12 months (OR 2.5, p < 0.001 for adults with asthma, OR 1.8, p < 0.01 for parents of children with asthma) and morbid obesity (OR 3.4, p < 0.001 for adults with asthma). Among adults who reported one or more episodes of asthma in the past 30 days, 28% of women and 30% of men had not used a preventive medication, and 48% of women and 57% of men had not used a prescription asthma inhaler (20% had not used either). This study adds to the scarce body of literature on the prevalence of asthma and related risk factors in a predominately Mexican-American, semi-rural community, and illustrates how survey and key informant data can enhance knowledge of local study populations and guide interventions to improve asthma control and treatment.