In a medium bowl, combine the cucumbers, onions, and bell pepper.
In a small saucepan, combine the vinegar, sugar, pickling salt, mustard seed, and celery seed. Bring to a boil over medium-high heat. Reduce the heat to low and simmer for 5 minutes.
Pour the hot liquid over the cucumber mixture and stir to combine. Allow to cool to room temperature.
Transfer to an airtight container and refrigerate for at least 2 hours before serving.
Interesting Facts
Sweet pickle relish is an American condiment typically served with hot dogs and hamburgers.
It is a popular condiment in the South of the United States.
Sweet pickle relish is also known as "sweet relish" or "chow-chow".