Series-connecting LEDs

I'd like to series-connect an array of five super-brighr LEDs.
Are there any problems that might show up in a few weeks or months if I do this? Are there any special considerations?
I assume that the current would be the same as for one, and the total voltage across the array would be five times the forward voltage for one LED.
I can calculate the series resistor for the voltage output of the power supply.
Your help will be appreciated.
Mark

Series connecting will work fine. Take the voltage drop of all 5 LEDs into consideration when calculating the resistor value. The total current through all LEDs will be the same.

If each LED has +/- 1v tolerance on the fwd voltage the overall tolerance on the fwd voltage of the string of five will be +/- 2.2v

It will work fine. Keep the current below the maximum design current of the leds to ensure a long term reliabilty.

e.g. 20 mA LED, run at 19 mA or less.

Calculate the series R by adding up all LED forward voltages and subtracting it from the supply voltage. Allowe for minor variations as already is suggested by the previous posters.