The main 'Pro' of hybrid cars is that they help save our environment because they reduce greenhouse gas emissions (CO2). In addition, smog-producing gases are reduced as much as a factor of 9, depending upon the gas and the car.
The main 'Con' of hybrid cars is the additional purchase cost (between $5,000 and $10,000). However, one can make up for that cost in gas price savings over enough years. To find out how many years, one should use a Fuel Savings Calculator.
A secondary con is that it requires a fair amount of energy to manufacture the NiMh (nickel metal hydride) batteries used in current hybrids. However, NiMh battery for a hybrid vehicle is only manufactured once for each vehicle that is likely to last 15 to 20 years, and when recycled the nickel is extracted (see Recycling Your Battery).
There are many additional issues. For example, Hybrid engines and drive trains have more parts and are mechanically more complicated, so long term maintenance costs will likely be higher. Hybrid batteries may need to replaced in as little as 10 years, at an typical $3000 expense if purchased today from the manufacturer. But that cost is likely to lower over the next 10 years.
This is a condensation of the full article, which can be found at: http://www.CompareHybridCars.net