Background : Mother -to- child transmission of HIV infection is the major source of infectionrnunder the age of 15 and global coverage of prevention of mother-to-child services reached 53%rnin 2009 .However, factors that influence utilization of PMTCT service and referral linkage tornchronic ART clinic for HIV positive pregnant women are not well studied in Hawassa town.rnObjective: To assess factors that influence utilization of PMTCT service and referral linkage tornchronic care before delivery in HIV positive pregnant women.rnMethods: Facility based cross sectional study was conducted in 6 Hawassa town public healthrnfacilities. Using systematic sampling procedure 588 study subject were included in the study. Indepthrninterview was also used to gather greater depth of information. A pretested structuredrnquestioner was used to collect data and the data analyzed using SPSS version 17. Moreover,rnbivariate and multivariate logistic regression model with crude and adjusted OR along with theirrn95% confidence interval were used to see the independent effect of factors influencingrnutilization of PMTCT service.rnResults: A total number of 588 pregnant women were included in this study. Five hundred thirtyrnone (90.3%) of the respondents reported they had under gone voluntary counseling and testingrnand 522(98.67%) of those who were tested received the test result and Four hundred ninetyrnnine (95.6%) were negative and twenty three (4.4%) were positive. Out of 23 women whornwere positive HIV status twenty women were linked to chronic ART care service 12 of themrnwith formal referral linkage and eight of with non-formal and nine of those who were linkedrnto chronic ART care service started HAART while seven started ARV prophylaxis. Pregnantrnwomen who were two or more number of ANC attendance were more likely to utilize PMTCTrnservice when compared to other sources [AOR=2.99% CI=1.44, 6.23]. The pregnant womenrnbelieved that their husbands support couple testing were associated with utilization of PMTCTrnservice [AOR=16.2,95% CI= 6.58, 39.67].The pregnant women who support the idea of everyrnpregnant should be tested also associated with utilization of PMTCT service [AOR=9.86, 95%rnCI=3.67, 26.51].rnConclusion: partner involvement, increasing access of women to VCT, community basedrneducation and sensitization targeted to the women and promoting PMTCT service to all facilityrnand improving referral system and getting feedback between facilities will create good referralrnsystem between facilities is recommended.rnVII