Development projects, particularly road is key in enhancing sustained economic development andrnsocietal transformation. However, negative environmental and social impacts of such projects are alsornextensive. Thus, concern for sustainability in managing such projects is critical. With this in mind, thernmajor objective of this study was to assess ESIA practice and its implication for project managementrnsustainability at Ethiopian Road Authority (ERA), Mojo-Hawassa Highway Project. Specifically, thernstudy assess practices of ESIA, investigate level of project management sustainability (PMS), examine thernnexus between ESIA practices and PMS, explain effects of ESIA practices on PMS, and identify majorrnchallenges faced while practicing ESIA. To this end, descriptive and explanatory research design withrnmixed approach was applied. Primary data was collected from key project staffs through questionnaire,rnKII and FGD guide. Accordingly, the study found out that there has been sufficient legal basis (M=3.96,rnSD=0.758), good institutional frameworks (M=3.74, SD=0.718), sound process of ESIA (M=3.98,rnSD=0.657) and better application of ESIA report (M=4.087, SD=0.611); implying sound ESIA practicesrnoverall. There has been encouraging concern for PMS as manifested by economic (M=3.80, SD=0.813),rnsocial (M=3.865, SD=0.698) and environmental (M=3.85, SD=0.769) sustainability. There has beenrnsignificant positive association between ESIA practices and PMS; and so overall practices of ESIA,rnsignificantly explain 40.1% of the variance in PMS. Thus, it is concluded that overall practices of ESIArnhas significant implication for PMS in the Highway Project. However, there have been challenges likernlack of sufficient national legislations and institutions dealing with social aspects; lack of sufficientrnprofessional man power; less commitment of contractors; inadequate RoW clearance and compensationrnpayment; inadequate and inconsistent cooperation from local administration and others. So, thernresearcher recommends regular consultation with key stakeholders; improving capacity of existing staffrnand due concern during staff hiring decision by all parties. Developing quality procedures for socialrnaspects and pushing higher government bodies for the same; and on-going follow up; and acknowledgingrnthose who perform good on sustainability by ERA has also be recommended.