From 1985 to 1995 the proportion of all Santa Clara County, California (SCC), tuberculosis (TB) cases among recent immigrants climbed 73% (137 to 237). In SCC the efficient and cost-effective means encouraging TB Class A/B1/B2 immigrants (TBIMs) to present for TB screening and the prevalence of active TB among them were never investigated. We studied all TBIMs entering SCC from October 1, 1995 to June 30, 1996, notified to SCC by the CDC's Division of Quarantine (DQ). Encouraging TBIMs to seek TB screening, we sent letters to them promptly on the DQ notification, followed sequentially by phone calls and home visits. We determined the outcome of screening and its cost. We screened 314 of 323 (97.2%) TBIMs including 79 of 323 TBIMs who presented prior to interventions, 213 of 314 (87.3%) who responded to letters, 17 (7%) to phone calls, and 5 (2%) to home visits. Of 283 TBIMs screened 16 (5.7%) had active TB. To locate one TBIM cost $9.90 by letter, $43.25 by phone, and $129.88 by home visit. Locating one TB case cost $175.88 by letter, $696.26 by phone call. The prevalence of active TB in TBIMs is high. Our interventions resulted in low-cost TB screening and high-yield identification of active TB cases. We recommended that health departments develop a system for encouraging TBIMs to present for prompt TB screening.