The study looked at how different ages and densities of rice seedlings affect crop performance and water productivity in Laos. Older seedlings with more tillers produced higher grain yields. Seedling density didn't affect yields but did impact other aspects of grain production. Shorter duration rice varieties needed less water than longer ones. Delayed transplanting increased total water productivity but decreased irrigation water productivity. The longer the delay in transplanting, the longer the total crop growth duration. However, the time from transplanting to maturity decreased with each 10-day delay in transplanting. Choosing the right rice varieties and increasing seedling density can improve crop performance and water productivity when transplanting is delayed.