Background: Gestational weight gain (GWG) is increase in weight of pregnant women fromrnconception to delivery. It is an important factor that supports optimal outcome for mothers andrntheir infant. The risk of inadequate GWG among HIV positive women is higher as HIV increasesrnboth energy requirements and the risk of under nutrition. Nonetheless, comparative data onrngestational weight gain and its determinants among HIV negatives and HIVpositives are scarce.rnObjective: The objective of this study was to assess and compare gestational weight gain and itsrnassociated factors among HIV positive and HIV negative women in Addis Ababa.2017rnMethods: Institutional based comparative cross-sectional study wasemployed from April 2 â€“rnMarch 31, 2017 GC in Addis Ababa Ethiopia.558 study participants (372 HIV negative and 186rnHIV positive women) were selected.Data was entered into Epi Data version 3.1 and exported tornSPSS version 22 for analysis. Binary and multiple logistic regressions used to identify associatedrnfactors with the outcome variable. Texts, tables and graphs were used for descriptive statics.rnResults: overall 549 eligible women participated in the study making 98.4% response rate. Thernstudy finding reviled that the prevalence of GWG among HIV negative and HIV positive womenrnis low (30.7% and 26% respectively). This difference has no statically significance in chi-squarernanalysis. Factors associated with GWG among HIV negative women are family monthlyincomernin USD [AOR=4.35,95% CI(1.75-10.7)],Knowledge of fruits are main food typern[AOR=2.84,95% CI(1.5-7.6)], hours engaged in typical activity for less than two hours and forrnthree to four hours in typical day [AOR=1.32, 95% CI (1.06-3.49)],[AOR=4.65, 95% CI (1.76-rn12.29)] and early pregnancy BMI [AOR=13.9,CI 95% (4.26-45.87)] while women who had nornformal education[AOR=3.16 95% CI=(1.25-8.86)] andwomen whose family monthly incomernwas less than 50USD. [AOR=3.91, 95% CI=(1.02-15.2)] were the associated factors to GWGrnamong HIV positive women.rnConclusion and recommendations: The prevalence of adequate GWG among HIV negativernand HIV positive women is low, the probability of adequate GWG among HIV positive womenrnis much lower. Associated factors among the two groups are different with the exception ofrnmonthly income. So the two groups should be treated differently and different measures shouldrnbe taken in order to increase the prevalence of adequate GWG according to IOM.rnKey words: Gestational weight gain, HIV, Pregnancy