By Road and Air
Duration: 45-minute drive + 20-minute flight
Lumbini itself doesn't have an airport, but it is served by the nearby town of Siddharthanagar. Sometimes people refer to this as Lumbini Airport. It's 15 miles (25 km) south of Lumbini, just before you get to the Nepal-India border crossing at Sonauli, and takes about 45 minutes to get there by taxi.
From Siddharthanagar, one or two daily flights travel to Pokhara. The flight is very short, at just 20 minutes, and can save you hours on winding and uncomfortable roads.
By Private Transfer
Duration: 6 hours
If you have to make the trip from Lumbini to Pokhara overland, getting a private transfer is the easiest, quickest, and most comfortable option. The road between the two towns goes through Butwal and then climbs to Tansen, an attractive Newari hill town that is an ideal place to break the journey if you're not in a hurry. The road between Tansen and Pokhara is very windy and somewhat hazardous. With a private transfer you can stop and have a break if you feel car sick, or just to enjoy the views.
By Local Bus
Duration: 8+ hours
There are no tourist or direct buses between Lumbini and Pokhara. It's necessary to get one bus to Butwal, and then another to Pokhara. These leave relatively frequently throughout the day, but are slow and quite dangerous, especially as the road between Tansen and Pokhara is famously bad. Taking the bus is only really an option if you're on a very limited budget.