Everything you bring to Nicaragua  should be sturdy and ideally water-resistant, especially if you intend to visit the Atlantic coast or Río San Juan , where you’ll inevitably find yourself in a boat. Also be prepared for rain during any part of the wet season.
Choose a small, strong bag not so large you’ll be uncomfortable carrying it for long distances or riding with it on your lap in the bus—and secure its zippers with small padlocks. If you’re planning to stay in a midrange or upscale hotel for the duration of your trip, your bag is of less concern, but be sure to take a small daypack or shoulder bag for your daily walkabouts.
Pick clothes that are light and breathable in the heat, and if your plans include Matagalpa, Jinotega, or Estelí , you may appreciate something a bit warmer, like a flannel shirt. For sun protection, don’t forget a shade hat that covers the back of your neck.
No matter what your style, it is very important to look clean. Having a neat personal appearance is important to all Latin Americans, and you’ll find being well groomed will open a lot more doors. In the countryside, Nicaraguan men typically don’t wear shorts, unless they are at the beach or at home. Jeans travel well, but you will probably find them hot in places like León  and Chinandega ; khakis are lighter and dry faster.
Roads are rough, even in cities, so good walking shoes will ease your trip considerably; lightweight hiking boots or just sturdy sneakers are sufficient. You’ll be hard-pressed to find shoes larger than a men’s 10.5 (European 42) for sale in Nicaragua. Take a pair of shower sandals with you, or better yet, buy a pair of rubber chinelas anywhere in Nicaragua for about $1.
Bring a small first-aid kit, plastic bags and Ziplocs for protections from both rain and boat travel, and a cheap set of ear plugs for the occasional early-morning rooster or chichera band.
A lightweight, breathable raincoat and/or small umbrella are a good idea. A small flashlight or headlamp is indispensable for walking at night on uneven streets and for those late-night potty runs in your hospedaje, and an alarm clock will facilitate catching early-morning buses. If you wear glasses, bring along a little repair kit. Bring a pocket Spanish dictionary and phrasebook.
Photos of home and your family are a great way to connect with your Nica hosts and friends. A simple compass is helpful for finding your way around, as directions in this book typically refer to compass directions (finding the hotel three blocks north of the park is a lot easier if you know which direction north is).
Make a photocopy of the pages in your passport that have your photo and information. When you get the passport stamped in the airport, it’s a good idea to make a photocopy of that page as well after you get situated in your first hotel, and store the copies somewhere other than with your passport. This will facilitate things greatly if your passport ever gets lost or stolen. Also consider taking a copy of your health and medical evacuation insurance policy.