Maize is a staple food crop for small holder farmers in Northwestern part of Ethiopia. Cultivation of QPM provides an opportunity to farmers to produce nutritionally superior maize grains and fill nutrition gaps for those who don’t have access for protein derived from animals and animal products. However, QPM is not common for most farmers in Amhara region and has no production packages in Amhara region. Therefore, agronomic trials like intra row spacing is very crucial to come up with optimum production that will agitate farmers to accept the technology and produce QPM in their system. Hence, a field experiment was conducted to determine the effects of intra row spacing on different varieties of QPM in Koga Irrigation Scheme, North Mecha district of Amhara Region during 2021/22 under irrigation. The experiment consisted of the factorial combinations of three QPM varieties (Melkassa 1Q, Melkassa 6Q and MHQ-138) and four intra-row spacing (20, 25, 30 and 35 cm). The treatments were arranged in factorial combination in Randomized Complete Block Design with three replications. Data on phenology, vegetative growth, yield and yield component parameters were collected timely as per their respective standard procedures. Analysis of variance for the collected data was carried out using SAS version 9.4. The ANOVA also had shown that intra row spacing and QPM varieties influenced most of the tested parameters. Accordingly, the main effects of varieties were highly significantly affected days to 50% tasseling, days to 50% silking, days to maturity, leaf area index and plant height. Similarly, highly significant effect was observed in interaction effect of variety and intra-row spacing on ear height, biological yield, number of kernel per cob, thousand grain weight and grain yield. Results revealed that, higher grain yield and biological yield were obtained from melkassa 6Q sown at 30 cm intra row spacing which was 6.37 t ha−1 and 15.60 t ha−1, respectively. While the lowest grain yield (3.67 t ha−1) was obtained from 20 cm intra row spacing and melkassa 1Q variety. Moreover, planting Variety MHQ-138 at the same intra row spacing gave the 2nd higher grain yield. Therefore, it can be concluded that planting melkassa 6Q QPM variety at the intra-row spacing of 30 cm gave maximum grain yield and would be recommended for the mid altitude area under irrigation condition. For better confirmation of the results, this one year experiment needs to be repeated at multi-locations and in different seasons.