Background: The current embryo selection methods rely on subjective grading of embryo morphology or a real-time monitoring of the embryonic development and assessment of multiple quantitative endpoints. Even up to 40% of morphologically normal embryos harbour aneuploidies. Preimplantation genetic testing (PGT) is a technology, which gives opportunity to identify euploid embryos before implantation. Aims: This study seeks to determine the role of PGT in poor prognosis patients, i.e., patients with advanced maternal age (AMA) (maternal age ≥35 years), recurrent pregnancy loss (RPL) (miscarriages ≥2) and recurrent implantation failures (RIFs) (in vitro fertilisation failures ≥3). Setting and Design: A retrospective case-control study was done on a group of patients who underwent intracytoplasmic sperm injection for the indications of AMA, RPL and RIF. Materials and Methods: In 33 cases who opted for PGT, day 5 blastocysts were subjected to trophectoderm biopsy with the help of next-generation sequencing. Euploid blastocyst was transferred in hormone replacement cycle at a later date. In 154 controls, blastocyst transfer was done based on morphological grading. Pregnancy outcomes are compared in terms of implantation rate, pregnancy rate, miscarriage rate and multiple pregnancy rate. Statistical Analysis Used: Chi-square test was used for comparisons between the study groups with respect to percentage. P < 0.05 was considered statistically significant. Results: The highest aneuploidy rate was found in embryos with AMA. Implantation rate was found to be statistically significantly higher in the PGT group as compared to the non-PGT group. However, take-home baby rates were not improved by PGT. There were less number of mean embryos transferred in the PGT group and lower multiple pregnancy rate. Conclusions: With the application of PGT, embryo selection rates and implantation rates improved in poor prognosis patients.