They are supposed to be an easy way of making sure that you get things done.
But to-do lists actually make you less likely to finish all of your tasks, says a leadership expert.
Kevin Kruse said to-do lists are "where important tasks go to die" and that they can make you more stressed out.
Instead you should think in 15-minute blocks and schedule everything in your day so you don't waste a minute.
Studies have shown that nearly two in three professionals write to-do lists - but just 41 per cent of the items get completed.
Mr Kruse, a best-selling author whose books include 15 Secrets Successful People Know About Time Management, said that none of the 200 billionaires, entrepreneurs or Olympians he has interviewed use to-do lists. "Do you really think Richard Branson and Bill Gates write long to-do lists and prioritise items?" he said.
The problem with to-do lists is that they are not accurate because they do not account for the amount of time that things really take, Mr Kruse said.
They don't distinguish between what's important and what isn't, meaning that we do not prioritise properly.
All this adds to the stress of the working day and can lead to anxiety and insomnia, according to Mr Kruse.
Instead of to-do lists you should block off your calendar with time for the most important things, such as emailing or planning, so that you are not distracted.
Mr Kruse told website Fast Company: "Get clear on your life and career priorities, and preschedule sacred time blocks for these items." By thinking in 15 or 30-minute blocks you really assess how long a task takes before taking it on, he said.
Mr Kruse added: "Ultra-productive people only spend as much time as is necessary.
"Yahoo! chief executive Marissa Mayer is notorious for conducting meetings with colleagues in as little as five minutes. When your default setting is 15 minutes, you'll automatically discover that you can fit more tasks into each day."
And Mr Kruse said if you choose a time of the day for specific tasks and stick to it, your productivity will improve.
"When you are forced to pick a specific day and time, you will get the right things done on more consistent basis and your stress will go away," he said.
- Daily Mail