Blockchain technology introduced the blockchain for the successful conduct of digital currency transactions, but the technology is now being integrated into different fields, marketing inclusive. This research aims at analysing the impact of blockchain in promoting sustainable marketing through increasing the levels of transparency and consumer trust. Using a mixed-methods approach, the research addresses three key questions: how blockchain adds value in terms of transparency, problems that arise when implementing blockchain and how it affects consumer trust. Quantitative data were collected from 150 marketing professionals through a designed questionnaire, revealing high implementation rates for supply chain transparency (85%), ethical promotion (75%), and product authenticity verification (70%). The results disclose highly positive scores in aspects of transparency having a mean of 4.5 and the aspect of consumer trust having slightly lower mean of 4.2. In a Qualitative insights with 15 experiential experts through semi-structured interviews, highlight the benefits include an improved transparency 80% and increased consumer trust 75% but the challenges include high implementation costs 70%, technological complexity 65% and integration difficulties 60%. The study offers insights into the practical way of achieving sustainable marketing with the use of the blockchain technology and thereby calls for the establishment of way of addressing these challenges in order to maximize its efficiency.