Wastes are normally solids, useless and unwanted. However, many of these materials can be reused, recycled and thus they can become a resource if managed and treated properly. Rapid growth of population, urbanization and industrialization poses sharp increase of waste generation and change of its nature. Due to organizational limitations, lack of people’s awareness, absence of appropriate management, financial & resource constraints, ineffectiveness of legislation and law enforcement, wastes remain unmanaged and posed threat to human and nature, especially in the developing countries. To address this issue, Khulna University of Engineering & Technology (KUET) has taken several initiatives since 2002. In this footstep, to exchange the views and experiences at both the national and international levels on the modern technologies and sustainability of solid waste management (SWM), WasteSafe2009, WasteSafe 2011 and WasteSafe 2013, the 1st, 2nd and 3rd International Conference on Solid Waste Management in Developing Countries were organized successfully at Khulna in 9-10 November 2009, 13-15 February 2011 and 10-12 February 2013 respectively. The success of the event encouraged the organizer to continue such activities and hence the WasteSafe2015, the 4th International Conference on SWM in Developing Countries, is jointly organized at Khulna on 15-17 Feb. 2015 by · Khulna University of Engg. & Technology, Bangladesh · Bauhaus Universitat Weimer, Germany · University of Padova, Italy · International Waste Working Group (IWWG) · ORBIT Group It is expected that the researchers and professionals will unfold their latest findings and experiences in this forum in order to provide the necessary guidelines. Heartiest thanks to all organizations and/or individuals for rendering cooperation to accomplish this Conference in Khulna. WasteSafe 2015 welcomes all of you at Khulna and promise to have an interesting programme and many stimulating discussion