This study assessed the rate of primary infertility and its associated factors among 402,807 currently married women aged 20–49 years in India using National Family Health Survey-4 data collected in 2015–2016. Dietary patterns and selected morbidities were included as independent variables, and socioeconomic variables were considered as covariates. Bivariate and multivariate analyses were done to estimate the prevalence of primary infertility and assess its association with the selected variables, respectively. The rate of primary infertility among currently married women in India in 2015–16 was 1.9% and this was significantly associated with younger age (<35 years), higher age at marriage (≥18 years), urban residence, higher secondary or above education and poverty. The consumption of dairy products (OR = 0.79, CI = 0.73–0.86), dark green leafy vegetables (OR = 0.57, CI = 0.39–0.81) and fruit (OR = 0.88, CI = 0.77–1.01) significantly reduced the odds of primary infertility. Daily consumption of fish and aerated drinks was related to 1.06–1.21 times higher odds of primary infertility. Overweight/obesity, high blood pressure and high blood glucose levels were associated with 1.08–1.21 times elevated odds of primary infertility. Thyroid disorder (OR = 1.38, CI = 1.21–1.60), heart disease (OR = 1.17, CI = 1.16–1.19) and severe anaemia (OR = 1.24, CI = 1.00–1.53) were associated with an increased likelihood of primary infertility among women (OR 1.17–1.39, CI 1.00–1.60). The findings provide compelling evidence that primary infertility among women is related to dietary patterns and morbidities. Interventions and programmes targeting the promotion of healthy diets and lifestyles could be beneficial in addressing the issue of primary infertility among women.